You are standing next to a table and looking down on a record player sitting on the table. Take the spindle (axis of rotation) to be the center of your coordinate system and the y axis to be perpendicular to the side of the player you are standing next to. Long-playing records revolve 33(1/3) times per minute. You put a small blob of clay at the edge of a record that has a radius of 0.15 m, positioning the clay such that it is at its greatest value of y at t = 0.

Equation of motion for the y component of the clay's position: y(t)=Asin(ωt+ϕi)

Required:
a. What is the rotational speed of the clay?
b. Determine the value of A in the equation of motion.
c. Determine the value of ϕi in the equation of motion. Suppose that −π<ϕi≤π

Answers

Answer 1

Answer:

a) the rotational speed of the clay is  3.45 rad/s

b) the value of A in the equation of motion is 0.15 m

c) the value of ϕi is 90° or π/2 rad.

Explanation:

 Given that;

Revolution per minute rpm = 33( 1/3) =  100/3

The frequency f = 100 / 3(60) = 0.55 Hz

a)

Rotational speed W = 2πf

we substitute

W = 2π × 0.55

W = 3.45 rad/s

Therefore, the rotational speed of the clay is  3.45 rad/s

b)

given equation; y(t)=Asin(ωt+ϕi)

given that radius = 0.15 m

y(t)=(0.2)sin(ωt+ϕi)

Therefore, the value of A in the equation of motion is 0.15 m

c)

since y(t) has the maximum value at t =0

so at t=0

y(0) = (0.15)sin(ω(0)+ϕi)

= 0.15sin(ϕi)

this will give maximum value when ϕi = 90°

so

y(0) = (0.15)sin(ω(0)+ϕi)

= 0.15sin(90°)

= 0.15

hence, the value of ϕi is 90° or π/2 rad.


Related Questions

A ball is thrown vertically upward from the top of a 100 foot tower, with an initial velocity of 10 ft/sec. Its position function is s(t)=−16t2+10t+100.

a. What is its velocity in ft/sec when t = 2 seconds? (Solve by using instantaneous rate.)
b. Determine the equation of a line, in slope-intercept form, that passes through the points (5, 6) and (10, 2).

Answers

Answer;

-54ft/s

y = -4/5 x + 10

Explanation

Given the position of an object expressed by the function

s(t)=−16t²+10t+100

Velocity is the change in position with respect to time

v(t) = ds(t)/dt

v(t) = -32t + 10

When t = 2

v(2) = -32(2)+10

v(2) = -64+10

v(2) = -54

Hence the velocity of the object is -54ft/s

b) The standard equation of a line in point slope form is expressed as;

y = MX+c

M is the slope

c is the y-intercept

Given the coordinate (5, 6) and (10, 2)

M = 2-6/10-5

M = -4/5

Get the y-intercept

Substitute m = -4/5 and any point say (5,6) into the expression y = mx+c

6 = -4/5 (5) + c

6 = -4+c

c = 6+4

c = 10

Get the required equation

Recall that: y = mx+c

y = -4/5 x + 10

Hence the equation of a line, in slope-intercept form is y = -4/5 x + 10

a student lift a 25kg mass at vertical distance of 1.6m in a time of 2.0 seconds. a. Find the force needed to lift the mass (in N ). b. Find the work done by the student (in J). c. Find the power exerted by the student (in W)

Answers

Answer:

a. F = 245 Newton.

b. Workdone = 392 Joules.

c. Power = 196 Watts

Explanation:

Given the following data;

Mass = 25kg

Distance = 1.6m

Time = 2secs

a. To find the force needed to lift the mass (in N );

Force = mass * acceleration

We know that acceleration due to gravity is equal to 9.8

F = 25*9.8

F = 245N

b. To find the work done by the student (in J);

Workdone = force * distance

Workdone = 245 * 1.6

Workdone = 392 Joules.

c. To find the power exerted by the student (in W);

Power = workdone/time

Power = 392/2

Power = 196 Watts.

what is the pressure on a swimmer 50 m below the surface of a lake​

Answers

Answer:

P = 490500 [Pa]

Explanation:

The pressure at the bottom of a vessel and even of a lake or sea can be calculated by means of the following hydrostatic equation.

[tex]P=Ro*g*h[/tex]

where:

P = pressure [Pa] (units of pascal)

Ro = water density = 1000 [kg/m³]

g = gravity acceleration = 9.81 [m/s²]

h = elevation = 50 [m]

Now replacing:

[tex]P=1000*9.81*50\\P=490500[Pa][/tex]

If a car is traveling at an average speed of 20 m/s, how long will it take to travel 500 meters?
A. 0.04 seconds
B. 25 seconds
C. 520 seconds
D. 10,000 seconds

Answers

Answer:

B. 25 seconds

Explanation:

500÷20=25

500/20=25
B.25 seconds

What is the function
of second plate in
parallel plate capacitor?​

Answers

A parallel plate capacitor consists of two large plane parallel conducting metal plates separated by a small distance. The second plate acts as a neighbouring conductor due to which the potential of first plate is reduced, keeping its size same ;due to which the capacitance increases.

a) A bus of mass 760 kg requires 120 m to reach certain velocity value Vf. Ignore friction and drag forces and assume the bus engine exerts a constant forward force F. When the bus is towing a 330-kg small car, how long distance needed to reach same Vf? b) If the Vf of the bus is 28 m/s, what is the tension in the tow cable between bus and small car?

Answers

Answer:

Given :  A bus of mass 760 kg requires 120 m to reach certain velocity value Vf.

the bus engine exerts a constant forward force F.

To Find : When the bus is towing a 330-kg small car, how long distance needed to reach same Vf?

Solution:

V²  - U² = 2aS

V = Vf

U = 0

S = 120 m

=> Vf² - 0 = 2a(120)

=> Vf² = 240a

m = 760  kg

Force = F

F = ma

=> F =760 a

=> a = F/760

Vf² = 240F/760

Case 2  :When the bus is towing a 330-kg small car,

m = 760 + 330 = 1090 kg

a = F/1090

Vf²  = 2aS

=> 240F/760  = 2 (F/1090) S

=> S = 120 x 1090 /760

=> S = 172.1   m  

172.1   m   distance needed to reach same Vf

Explanation:

Sultan walks for 15 km at 35° south of east.
Which of the following journeys would result in the same displacement?

Answers

Answer:

Explanation:

Introduction: The specific heat capacity of a substance is the amount of energy needed to change the temperature of that substance by 1 °C. Specific heat capacity can be calculated using the following equation:
q = mc deltaT
In the equation q represents the amount of heat energy gained or lost in joules), m is the mass of the substance (in grams), c is the specific heat capacity of the substance (in J/g °C), and AT is the temperature change of the substance in °C).
Goal: Calculate the specific heat capacities of copper, granite, lead, and ice.
Solve: When you mix two substances, the heat gained by one substance is equal to the heat lost by the other substance. Suppose you place 125 g of aluminum in a calorimeter with 1,000 g of water. The water changes temperature by 2 °C and the aluminum changes temperature by -74.95 °C.
A. Water has a known specific heat capacity of 4.184 J/g °C. Use the specific heat equation to find out how much heat energy the water gained (q).
B. Assume that the heat energy gained by the water is equal to the heat energy lost by the aluminum. Use the specific heat equation to solve for the specific heat of aluminum. Aluminum's accepted specific heat value is 0.900 J/g °C. Use this value to check your work.

Answers

Answer:

A) 8,368 J

B) ) 0.893 J/gºC

Explanation:

A)

The heat gained by the water can be obtained solving the following equation:

       [tex]q_{g} = c_{w} * m * \Delta T (1)[/tex]

where cw = specific heat of water = 4.184 J/gºCm= mass of water = 1,000 gΔT = 2ºC Replacing these values in (1) we get:

       [tex]q_{g} = c_{w} * m * \Delta T = 4.184 J/gºC*1,000 g* 2ºC = 8,368 J (2)[/tex]

B)

Assuming that the heat energy gained by the water is equal to the one lost by the aluminum, we can use the same equation, taking into account that the energy is lost by the aluminum, so the sign is negative:  -8,368 J.Replacing by the mass of aluminum (125 g), and the change in temperature (-74.95ºC), in (1), we can solve for the specific heat of aluminum, as follows:

       [tex]q_{l} = c_{Al} * m_{Al} * \Delta T (3)[/tex]

⇒    [tex]-8,368 J = c_{Al}* 125 g * (-74.95ºC) (4)[/tex]

       [tex]c_{Al} = \frac{-8,368J}{125g*(-74.95ºC} = 0.893 J/gºC (5)[/tex]

which is pretty close to the Aluminum's accepted specific heat value of 0.900 J/gºC.

If an atom of oxygen has an atomic number of eight that means...…
E. there are 8 protons
F. there are 8 neutrons
G. it weighs 8 amu
H. it is in group 8

Answers

E is your answer! protons and the atomic number will always be the same
E us your answer. there are 8 protons.

A spring stretches by 15cm when a mass of 300g hangs down from it,if the spring is then stretched an additional 10cm and released, calculate;the spring constant,the angular velocity, amplitude of oscillation, maximum velocity, maximum acceleration of the mass,period, frequency​

Answers

Answer:

0.1 m

Explanation:

It is given that,

Mass of the object, m = 350 g = 0.35 kg

Spring constant of the spring, k = 5.2 N/m

Amplitude of the oscillation, A = 10 cm = 0.1 m

Frequency of a spring mass system is given by :

Time period:

Lisa skips 5 m North to the playground. She realizes she forgot to bring water so she turns around and goes 3 m South to the convenience store

Answers

Answer:

-2 South

Always subtract where they ended first is what my teacher said

the diameter of the wheels on your car ( including the tires) is 25 inches. you are going to drive 250 miles today. each of your wheels is goingnto turn by an angle of​

Answers

So the answer is 324.

Explanation
Because I took that test and I got right if u don’t believe me u can brainy it

Two 2.1-cm-diameter electrodes with a 0.20-mm-thick sheet of Teflon between them are attached to a 9.0 V battery. Without disconnecting the battery, the Teflon is removed.

Required:
a. What is the charge before the Teflon is removed?
b. What is the potential difference before the Teflon is removed?
c. What is the electric field before the Teflon is removed?
d. What is the charge after the Teflon is removed?
e. What is the potential difference after the Teflon is removed?
f. What are the electric field after the Teflon is removed?

Answers

Answer:

a. Q = 1881.73 x [tex]10^{-13}[/tex] C

b. As battery is not removed so, potential difference will remain same.

c. E = 21.42 x [tex]10^{3}[/tex] V/m

d. Q = 895.5 x [tex]10^{-13}[/tex] C

e. Again the potential difference will not change it will remain same as 9 V

f. E = 45 x [tex]10^{3}[/tex] V/m

Explanation:

Solution:

Here, Teflon is used so, the dielectric constant of the Teflon K = 2.1

Diameter = 2.1 cm

Radius = 2.1/2 cm

Radius = 1.05 cm

Radius = 0.015 m

Now, we need to find the area of each plate:

A = [tex]\pi r^{2}[/tex]

A = (3.14) ([tex]0.015^{2}[/tex])

A = 0.000225 [tex]m^{2}[/tex]

A = 2.25 x [tex]10^{-4}[/tex] [tex]m^{2}[/tex]

We are given the thickness of the plate which equal to the distance between the two plates.

d = 0.20 mm = 0.2 x [tex]10^{-3}[/tex] m

d = 0.2 x [tex]10^{-3}[/tex]  m = distance between two plates.

Hence, the capacitance of the dielectric without the dielectric

C = [tex]\frac{E.A}{d}[/tex]

Putting up the values we get,

E = 8.85 x [tex]10^{-12}[/tex]

C = [tex]\frac{8.85 . 10^{-12} x 2.25 . 10^{-4} }{0.002}[/tex]    

C = 99.5 [tex]10^{-13}[/tex]

If dielectric is included then,

[tex]C^{'}[/tex] = K C

[tex]C^{'}[/tex] = (2.1) ( 99.5 x [tex]10^{-13}[/tex])

[tex]C^{'}[/tex] = 209.08 x [tex]10^{-13}[/tex] F

As we know the voltage of the battery V = 9V So,

a) Charge before the Teflon is removed:

Q = CV

Q = [tex]C^{'}[/tex]V

Q = (209.08 x [tex]10^{-13}[/tex] F) (9V)

Q = 1881.73 x [tex]10^{-13}[/tex] C

b) Potential Difference before the Teflon is removed = ?

As battery is not removed so, potential difference will remain same.

c) Electric Field =?

As we know,

E = V/(K.d)

E = 9V/(2.1 x 0.2 x [tex]10^{-3}[/tex])

E = 21.42 x [tex]10^{3}[/tex] V/m

d) After the Teflon is removed

Q = CV

Q = (99.5 [tex]10^{-13}[/tex] ) ( 9)

Q = 895.5 x [tex]10^{-13}[/tex] C

e) Again the potential difference will not change it will remain same as 9 V

f) Electric Field = ?

E = [tex]\frac{V}{d}[/tex]  (Teflon is removed)

E = 9/0.2 x [tex]10^{-3}[/tex]

E = 45 x [tex]10^{3}[/tex] V/m

In which part of a lab report would be the following sentence most likely occur? “Since the data showed that the

Answers

We’re are the answer choices at?

Answer:

most likely be included in the analysis section of a lab report

Explanation:

PLS HELP ME!
A motorist is traveling 40ms-¹ and applies brakes and slow down at a rate of 2ms-² the available distance for the the motorist to stop is 400m will the motorist be able to stop?

Answers

Answer:

[tex] \underline{ \boxed{ yes}}\\[/tex]

Explanation:

[tex]given : initial \: velocity \: (u )= 40 {ms}^{ - 1} \\ given : final \: velocity \: (u )= 0 {ms}^{ - 1} \\ given : - (acceleration) \: (a_r) = 2 {ms}^{ - 2} \\ given : distance \: (s) \: = \: ? : \\ but \: {v}^{2} = {u}^{2} + 2( a)s\\ {0}^{2} = {40}^{2} + 2( - 2)s \\ - {40}^{2} = - 4s \\ s = \frac{ - {40}^{2} }{ - 4} \\ s = \frac{1600}{4} \\s = 400 \: m[/tex]

I need this done by tonight!! Can anyone help me please? Answer these 4 questions

Answers

Answer:

1. 14 g of chocolate mixture.

2. 24 fl oz of chocolate milk

3. 10 cups of chocolate milk.

4. 12½ cups.

Explanation:

From the question given above, the following data were obtained:

1 TBSP = 7 g

1 Cup = 8 fl oz

2 Table spoons (TBSP) for 1 cup (8 fl oz) of milk.

1. Determination of the mass of chocolate mixture in 1 cup of chocolate milk.

From the question given above,

1 Cup required 2 Table spoons (TBSP)

But

1 TBSP = 7 g

Therefore,

2 TBSP = 2 × 7 = 14 g

Thus, 1 Cup required 14 g of chocolate mixture.

2. Determination of the number fl oz of chocolate milk in 3 cups

1 Cup = 8 fl oz

Therefore,

3 Cups = 3 × 8

3 Cups = 24 fl oz

Thus, 24 fl oz of chocolate milk are in 3 cups.

3. Determination of the number of cups of chocolate milk produce from 20 TBSP.

2 TBSP is required to produce 1 cup.

Therefore,

20 TBSP will produce = 20/2 = 10 Cups.

Thus, 10 cups of chocolate milk produce from 20 TBSP.

4. Determination of the number of cups obtained from 100 fl oz chocolate milk.

8 fl oz is required to produce 1 cup.

Therefore,

100 fl oz will produce = 100 / 8 = 12½ cups.

Thus, 12½ cups is obtained from 100 fl oz chocolate milk.

You are holding two balloons of the same shape and size. One is filled with helium, and the other is filled with ordinary air. On which balloon the buoyant force is greater?
a. The helium filled balloon experiences the greater buoyant force.
b. The air filled balloon experiences the greater buoyant force.
c. Both balloons experiences same buoyant force.

Answers

Answer:

Both balloons experiences same buoyant force.

Explanation:

Buoyant force is defined as the upward force that is exerted on an object which is wholly or partly immersed in a fluid. We can also define it as the upward force exerted by any fluid upon a body immersed in it. We may also refer to this buoyant force as the upthrust.

This buoyant force is the push of air on the balloon and it is independent of the contents of the balloons. Hence, both balloons experiences same buoyant force.

____ is factual information not subject to bias.

Interpretation
Analysis
Data
Opinion

Answers

Answer:

Data

Explanation:

Data is factual information not subject to bias.

This ultimately implies that, data connotes fact, thus, it is an information that is credible, accurate, a statement of truth, evidential and proven.

In Computer programming, a data dictionary can be defined as a centralized collection of information on a specific data such as attributes, names, fields and definitions that are being used in a computer database system.

In a data dictionary, data elements are combined into records, which are meaningful combinations of data elements that are included in data flows or retained in data stores.

This ultimately implies that, a data dictionary found in a computer database system typically contains the records about all the data elements (objects) such as data relationships with other elements, ownership, type, size, primary keys etc. This records are stored and communicated to other data when required or needed.

What relationship must exist between an applied force and the velocity of a moving object if uniform circular motion is to result?

Answers

Note that the centripetal force is proportional to the square of the velocity, implying that a doubling of speed will require four times the centripetal force to keep the motion in a circle.

Answer:

See explanation

Explanation:

Centripetal force is defined as the inward force required to keep an object moving with a constant speed in a circular path.

The magnitude of this force depends on the mass of the object, radius of the object and the velocity of the body.

So we can write;

F = mv^2/r

Which is the best explanation for why Toms technique works ?

Answers

I believe the correct answer is B

In designing buildings to be erected in an area prone to earthquakes, what relationship should the designer try to achieve between the natural frequency of the building and the typical earthquake frequencies?
A) The natural frequency of the building should be exactly the same as typical earthquake frequencies.
B) The natural frequency of the building should be almost the same as typical earthquake frequencies but slightly lower
C) The natural frequency of the building should be very different frem typical earthquake frequencies
D) The natural frequency of the building should be almost the same as typical earthquake frequencies but slightly higher.

Answers

Answer:

C) The natural frequency of the building should be very different from typical earthquake frequencies

Explanation:

We shall apply the concept of resonance in this problem .

When a body is applied an external harmonic force ( forced vibration) such that natural frequency of body is equal to frequency of external force or periodicity of external force , the body vibrates under resonance ie its amplitude of vibration becomes very high .

In the present case if natural frequency of building becomes equal to the earthquake's frequency ( external force ) , the building will start vibrating with maximum amplitude , resulting into quick collapse of the whole building . So to avoid this situation , natural frequency of building should be very different from typical earthquake frequencies .

describe measurement in our daily life​

Answers

We’re all pretty active and do a lot

A 71-kg swimmer dives horizontally off a 500-kg raft. If the diver's speed immediately after leaving the raft is 6m/s, what is the corresponding raft speed?

Answers

Answer:

The answer is below

Explanation:

Momentum is used to measure the quantity of motion in an object. Momentum is the product of mass and velocity.

Momentum = mass * velocity

The principle of conservation of momentum states that momentum cannot be created or destroyed but  can be transferred. Therefore the momentum before and after an action is equal.

Initial momentum = Final momentum

Let m be the mass of the diver, M be the mass of the raft, u be the initial velocity of the diver, U be the initial velocity of the raft, v be the final velocity of the diver and V be the final velocity of the raft.

m = 71 kg, M = 500 kg, v = 6 m/s

Initial both the raft and diver are at rest, hence u and U is zero, hence:

mu + MU = mv + MV

71(0) + 500(0) = 71(6) + 500(V)

0 = 426 + 500(V)

500(V) = -426

V = -426/500

V = -0.852 m/s


Can a single atom be considered a molecule?
A:only if the atom is found in water
B:no, it takes two or more atoms bonded to create a molecule
C:only if it is an oxygen atom floating in the air
D:yes, all atoms are made up of many different molecules

Answers

Answer is B. Atoms must be bonded together to create molecules.

Our Sun’s mass is 1.0 and our Earth’s mass is 2.0. The distance is standard as given on the simulation. Describe the path of the Earth.

Answers

Answer:

Earth orbits the Sun at an average distance of 149.60 million km (92.96 million mi), and one complete orbit takes 365.256 days (1 sidereal year), during which time Earth has traveled 940 million km (584 million mi).

Explanation:

Many scientific studies have found that colds are caused by viruses. What is this? *

Fact
Interpretation
Analysis
Opinion

Answers

Can you help me with my biology I just posted a couple of questions????

A safety plug is designed to melt when the pressure inside a metal tank becomes too high. A gas
at 51.0 atm and a temperature of 23.0°C is contained in the tank, but the plug melts when the
pressure reaches 75.0 atm. What temperature did the gas reach?

Answers

The plug is 6 but u have to divert by the scale to form 5 .C

A 62 kg student, starting from rest, slide down an 10.6 m high water slide. How fast is he going at the bottom of the slide? Use g = 10 m/s2

Answers

Answer:

14.6m/s

Explanation:

Given parameters:

Mass of the student  = 62kg

Initial velocity  = 0m/s

Height of slide = 10.6m

g  = 10m/s²

Unknown:

Speed at the bottom of the slide = ?

Solution:

The speed at the bottom of the slide is the final velocity;

             v ² = u²  + 2gh

v is the final velocity

u is the initial velocity

g is the acceleration due to gravity

h is the height

             v² = 0²  +  2x 10 x 10.6

             v²  = 212

              v  =  14.6m/s

What is the instantaneous velocity of a freely falling object 11 s after it is released from a position of rest

Answers

Answer:

v= -107.8 m/s

Explanation:

Since the object is in free fall, this means that is moving at an accceleration equal to the one due to gravity.Since it starts at rest, we can apply the definition of acceleration, rearranging terms as follows:

       [tex]v_{f} = v_{o} + a*t = a*t = -g*t = 9.8m/s2*11s = -107.8 m/s (1)[/tex]

(Assuming as positive the upward direction)

A teacher places a warm bottles in a cooler filled with ice. Which statement best explains what happened over time?

A) Thermal energy will move from ice to water bottles
B) Coldness will move from the water bottles to the ice.
C) Coldness will move from the ice to the water bottlers
D) Thermal energy will move from the water bottle to the ice.

Answers

Answer:

D) Thermal energy will move from the water bottle to the ice.

Explanation:

Overtime, what happens is that thermal energy will move from the water bottle to the ice.

The water bottle is at a higher temperature compared to the ice. So, thermal energy will move from a place at higher temperature to one with lower temperature.

Thermal energy will stop moving until thermal equilibrium is attained. The water bottle will lose heat to the ice and by so doing it becomes colder. The ice will gain heat and begins to warm up
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Which is the most common type of precipitation?hailrainsleetsnow Give an example of how structure and function are related on the cellular level. Daniel's age is 15% ofSarah's. Luke's age is 75% ofSarah's and 300% of Daniel's.When they added their ages,the total was 141. How old isRachel? Help me I'm too tired to think and this is easy. Please tell me if this number is greater than, less than or equal to 5. The number is -(-5) C. Choose the correct form of the irregular verb based on the subject. (ser, estar, ir)11) T _______ alto.a. soy b. eres C. son d. somos12) Ellas ______ bonitas.a. soy b. eres C. esd. son13) Nosotros _______ a la escuela.a. voy b. vamos c. va d. van14) Los estudiantes _______ trabajadores.a. es b. eres C. somosd. son15) Mara _______ en Florida de vacaciones.a. ests b. est c. estoy d. estn What do immigrants often share with other Americans?A. Another languageB. How to drawC. Where to parkD. Words to songs A mixture is made by combining 1.61 lb of salt and 5.37 lb of water. What is the percentage of salt (by mass) in this mixture? What statement is true about vines in the rainforest biome?A) They grab onto several trees to gain access to sunlight.B) They keep the structure of the canopy intact.C) They can grow up to 3,000 ft long.D) All of the abovePLS HELP ASAP How did Professor Andradetest whether people who doodleare actually paying attention? If Minnie the Mouse starts moving at 2m/s and increases her velocity to 4m/s because she is being chased, what is heracceleration if the time is 2 seconds? How to get 6/9 as a decimal using division help Help please im terrible at maths !! i need to find a book to write a report on but i havent come across any good onesgot any suggestions? Althea paid $5.00 each for two bracelets and later sold each for $15.00. She paid $8.00 each for three braceletsand sold each of them for $9.00.a. Write an expression that represents the profit Althea made.b. Evaluate the expression. Name the property used in each step. 3. Q3) What is the smallest number of identical squaresthat will fit in this rectangle? 0.110 is _____ than 0.450?A. lessB. greaterC. equalD. greatest A fish is swimming at a constant rate toward the ocean floor. The equation y = -7x - 3 can be used to represent this situation, where y is the depth of the fish in meters below sea level and x is the number of seconds the fish has been swimming. Someone please help! Im willing to pay for someone to help me with my five problems! Construct an explanation using Newton's Laws of Motion to describe the effects of balanced and unbalanced forces on the motion of an object.