A delivery boy on a bicycle drags a wagon full of newspapers by pedaling at 0.90 m/s for 45 minutes using a force of 40 N. How much work has the boy done?

Answers

Answer 1

Answer:

Explanation:

The equation for work is

W = FΔx

We are looking for work, so that means we have to be able to fill in the Force and the displacement. We have Force, but we don't have displacement. But the thing we need to do first is change the 45 minutes to seconds because the velocity is in m/s, not m/min.

45 minutes is 2700 seconds.

That means that  the displacement is

Δx = (.90)(2700) so

Δx = 2430 m

Now we plug that in to find work, along with the given Force:

W = 40(2430) so

W = 97200 J (and that is not the correct number of sig fig's but I have a feeling you're not too into that in class, because if you were, the 40 N would be expressed as 40.0 or 4.0 × 10¹)


Related Questions

A system consists of multiple objects connected by ropes. How many equations need to be written to solve this problem?

A) two for each object
B) one or two for each object
C) one for each object
D) two for the system

Answers

Answer:

the correct answer is B

Explanation:

To solve the system they must have the same amount of unknowns as equations,

a) If the system does not have friction, we must write the x-axis equation for each body, therefore we need to write N equations

b) if the system has friction, two equations are needed for each particle

therefore the correct answer is B

what happens to the force when the distance increases between 2 particales​

Answers

It goes faster or slower because there is more space inbetween

What is the correct equation for the y axis of object B?

Answers

Answer:

[tex]N_B-W_B = 0[/tex]

Explanation:

There are two forces acting on object B. If we consider the law of equilibrium, then the two forces must be equal in magnitude, for the object to remain in equilibrium position:

[tex]N_B = W_B\\\\N_B-W_B = 0[/tex]

Therefore, the correct answer of the given question, from the given choices, is:

[tex]N_B-W_B = 0[/tex]

Assertion: When I P+ Q I = I P- QI, then P must be perpendicular to Q. Reason: The relation will hold even when Q is a null vector.

Answers

Answer:

The assertion is true and reason is false.

Explanation:

Assertion: I P+ Q I = I P- QI, then P must be perpendicular to Q.

Reason : The relation will hold even when Q is a null vector.

Now

[tex]\left | P + Q \right |=\left | P - Q \right |\\\\P^2 + Q^2 + 2 P Q cos \theta =P^2 + Q^2 - 2 P Q cos \theta\\\\4 P Q cos \theta = 0 \\\\cos \theta = 0 \\\\\theta = 90 degree[/tex]

So, P and Q are perpendicular to each other.

So, the assertion is true.

Reason is false.

prove that vector addition obeys commutative and associative laws​

Answers

the order of vector addition doesn't affect the resultant vector and grouping or order of pair doesn't effect the sum.

Can somebody help me understand this

Answers

I think it’s C. Marshmallow and toothpicks are used to show the composition of a water molecule

The brakes in car A and car B stop working and they need to stop. Car A and car B have the same mass. Car A is traveling at 30 miles per hour, smashes into a big wall, and is brought to rest in a collision that lasts for a fraction of a second. Car B was also traveling at 30 mph but it drives out into a field of grasses and sand and finally comes to rest after a bumpy 20 second ride. Which car gets the larger impulse?

Answers

Answer:

Both have equal impulse.

Explanation:

Let the mass of cars be m.

Then the Force acting on each of them for taking them to state of rest:

(Using Newton's second law of motion)

[tex]F_A=\frac{m\times (0-30)}{\Delta t_A}[/tex]

[tex]F_A=-30\frac{m}{\Delta t_A}[/tex] ...................................(1) (negative sign is associated with direction, here we are concerned about the magnitude only)

[tex]F_B=\frac{m\times (0-30)}{\Delta t_B}[/tex]

[tex]F_B=-30\frac{m}{\Delta t_B}[/tex] ...................................(2)

[tex]\because \Delta t_A<\Delta t_B[/tex]

[tex]\therefore F_A>F_B[/tex]

We know that impulse is given as:

[tex]J=F\times \Delta t[/tex] ........................................(3)

So, from eq. (1), (2) & (3)

[tex]J_A=F_A\times \Delta t_A[/tex]

[tex]J_A=-30m[/tex]

&

[tex]J_B=F_B\times\Delta t_A[/tex]

[tex]J_B=-30m[/tex]

Hence both have equal impulse.

A squirrel jumps into the air with a velocity of 4 m/s at an angel of 50 degrees. What is the maximum height reached by the squirrel?

Answers

Answer:

Explanation:

Assuming the squirrel is jumping off the ground, here's what we know but don't really know...

v₀ = 4.0 at 50.0°

So that's not really the velocity we are looking for. We are dealing with a max height problem, which is a y-dimension thing. Therefore, we need the squirrel's upward velocity, which is NOT 4.0 m/s. We find it in the following way:

[tex]v_{0y}=4.0sin(50.0)[/tex] which gives us that the upward velocity is

v₀ = 3.1 m/s

Moving on here's what we also know:

a = -9.8 m/s/s and

v = 0

Remember that at the very top of the parabolic path, the final velocity is 0. In order to find the max height of the squirrel, we need to know how long it took him to get there. We are using 2 of our 3 one-dimensional equations in this problem. To find time:

v = v₀ + at and filling in:

0 = 3.1 - 9.8t and

-3.1 = -9.8t so

t = .32 seconds.

Now that we know how long it took him to get to the max height, we use that in our next one-dimensional equation:

Δx = [tex]v_0t+\frac{1}{2}at^2[/tex] and filling in:

Δx = [tex]3.1(.32)+\frac{1}{2}(-9.8)(.32)^2[/tex] and using the rules for adding and subtracting sig fig's correctly, we can begin to simplify this:

Δx = .99 - .50 so

Δx = .49 meters

Why would an airplane flying at 10,000 meters above the ground have more gravitational potential
energy than the same airplane flying at 1,000 meters above the ground?

Answers

Answer:

The gravitational potential energy (gpe) possessed by an object or body is directly proportional to the height of the object or body.

Explanation:

Gravitational potential energy (GPE) is an energy possessed by an object or body due to its position above the earth.

Mathematically, gravitational potential energy is given by the formula;

G.P.E = mgh

Where;

G.P.E represents potential energy measured in Joules.

m represents the mass of an object.

g represents acceleration due to gravity measured in meters per seconds square.

h represents the height measured in meters.

Generally, the gravitational potential energy (gpe) of an object or body is directly proportional to the height of the object or body. Thus, the gravitational potential energy of a body increases as the height of the body increases.

In conclusion, an object with a higher height would have a higher gravitational potential energy.

What is the current flowing through the circuit shown? (V= 110 V, R, = 200, R2 = 300, R3 = 10 0) (Ohm's law: V = IR)
A. 1.8 A
B. 20 A
C. 0.05 A
D. 0.55 A​

Answers

Answer:

A

Explanation:

The first thing you have to do is go back and list the resistances correctly. R1 = 20 R2 = 30 and R3 = 10.

Leave the units off if you can't make an omega.

The resistance of a series circuit (that's what this is) is r1 + r2 + r3 = 10 + 20 + 30 = 60 ohms

Now use ohms law.

R = 60 ohms

V = 110 volts.

I = V / R

I = 110/60

I = 1.833 to the nearest 1/10 = 1.8

In 'coin on card' experiment a smooth card is used. ​

Answers

Answer:

In coin card experiment smooth card is used so that the card can slide easily from glass

In three words I can sum up everything I’ve learned about life: it goes on. ― Robert Frost

What is an electric fuse? What is the working principle of electric fuse?

Answers

What is an electric fuse?Answer: Electric fuse is a safety device used to limit the current in an electric circuit which melts and breaks the circuit whenever there is an excess flow of current through the circuit.What is the working principle of electric fuse?An electric fuse is based on the principle of heating effect of electric current. It is made up of thin metallic wire of non-combustible material. A fuse is always connected between the ends of the terminal in a series connection with the circuit.

A scientist that applies the laws of science to the needs of communities is called _____.

the experimental scientist
the engineer
the teacher
the technician

Answers

Answer:

The experimental scientist

Gas to liquid with explanation on the basis of kinetic model and condensation point.​

Answers

Answer:

Explanation:

1)Melting:

Melting is the process by which a substance changes from the solid phase to the liquid phase. ... Melting occurs when the internal energy of a solid increases, usually through the application of heat or pressure, such that the molecules become less ordered.

2) liquefication:

In physics and chemistry, the phase transitions from solid and gas to liquid (melting and condensation, respectively) may be referred to as liquefaction. The melting point (sometimes called liquefaction point) is the temperature and pressure at which a solid becomes a liquid.

3) vaporization:

Vaporization, conversion of a substance from the liquid or solid phase into the gaseous (vapour) phase. If conditions allow the formation of vapour bubbles within a liquid, the vaporization process is called boiling. Direct conversion from solid to vapour is called sublimation.

4) Sublimation occurs as molecules of a substance in the solid state go to the vapor state directly, rather than through the liquid state. ... ⭕In terms of the kinetic molecular theory, we know that molecules are in constant random motion, even when the substance is below the melting point.

d. 'g' vanishes at centre of
6) A prism of 6° is made of material of refractive index What is the
deviation caused by it
d. 40
c.120
a. 60
b.8°
7) An object is placed 1cm from lens having magnification 5. Then its foc
length is
a. 0.8 cm b. 1.2 cm c. -1.2 cm d. -0.8cm​

Answers

Answer:

a. 0.8 cm

Explanation:

The distance of the object from the lens, u = 1 cm

The magnification of the lens, m = 5

The focus of a lens formula is given as follows;

[tex]f = \dfrac{1}{\dfrac{1}{v} + \dfrac{1}{v} }[/tex]

The magnification of the lens, m = -v/u

Where;

v = The distance of the image from the lens

Therefore, we have;

v = m × u

∴ v = 5 × 1 cm = 5 cm (on the other side of the lens)

From which we get;

[tex]f = \dfrac{1}{\dfrac{1}{1} + \dfrac{1}{5} } = \dfrac{5}{6} \approx 0.8[/tex]

The focal length ≈ 0.8 cm

If no braking occurs, a total of how much power would be required to keep the railcar moving at 40 m/s

Answers

Answer:

40 kW

Explanation:

A railcar has a continuous 1000 N decelerating force any time it is in motion. If no braking occurs, how much power would be required to keep the railcar moving at 40 m/s

Solution:

Power in Physics is the rate of doing work and the work can be mechanical, electrical, etc. The S.I unit of power is the watts (W).

The power required to keep the car moving must match the work done by the friction force (decelerating force) that tends to slow down the railcar.

Work done = Force * displacement

Power = Work done / time = (Force * displacement) / time

Power = Force * (displacement / time)

Power = force * velocity = 1000 N * 40 m/s = 40000 W

Power = 40 kW

a.in which portion of the curve,
1. is the velocity uniform.
2.is the velocity increasing.
3.is velocity decreasing.
4.is acceleration zero.

B. at which point does the body start to move and stop.
________________________


I will mark as brainlist​

Answers

Answer:

the answer is 4 acceleration is 0

Explanation:

this is because when parallel line is drawn through x axis the velocity will bw uniform

plz brainliest

Clothes are flung to the sides of a round tub during the spin-cycle of a washing machine.If the tub's period of rotation is 0.2s and the tub's radius is 35cm,answer the related qestions below: (a)The frequency of roation (b)The circumference of rotation (c)The spinning of speed (d)The centripetal acceleration (e)The centripetal force of rotation if total mass rotated is 30kg (f)The power of washing machine​

Answers

Answer:

Explanation:

First I need to tell you that I used .20 s for the period of rotation instead of just .2, and I used 30.0 kg for the mass instead of just 30. The reason being that both those numbers as stated in the problem only have 1 significant digit and that's not generally enough to get the accuracy you're looking for. Adding a 0 to the ends of each of those numbers doesn't change the value of the numbers, only the number of sig fig's in each. Beginning with a:

a. [tex]f=\frac{1}{T}[/tex] so [tex]f=\frac{1}{.2}[/tex] and f = 5.0 Hz

b. The circumference is the distance around the outside of the washer's drum. We need to find that, but before we do, I'm going to state the radius in meters instead of cm. 35 cm = .35 m. Therefore,

C = 2(3.1415)(.35) so

C = d = 2.2 m

c. The speed of the washer is found in d = rt, where r is the rate and our velocity and d is the distance around the outside of the drum (circumference). Therefore,

2.2 = v(.20) so

v = 11 m/s

d. The centripetal acceleration has an equation

[tex]a_c=\frac{v^2}{r}[/tex] so

[tex]a_c=\frac{(11)^2}{.35}[/tex] and

[tex]a_c=\frac{121}{.35}[/tex] so

[tex]a_c=350\frac{m}{s^2}[/tex]

e. The centripetal force has an equation

[tex]F_c=\frac{mv^2}{r}[/tex] and

[tex]F_c=\frac{(30.0)(11)^2}{.35}[/tex] and

[tex]F_c=[/tex] 1.0 × 10⁴ N

f. The equation for Power is

[tex]P=\frac{W}{t}[/tex] where W is work and W = FΔx (force times displacement). Therefore,

[tex]P=\frac{(1.0*10^4)(2.2)}{.20}[/tex] so

P = 1.1 × 10⁵ Watts

Is torque only produced when the force is applied perpendicular to the moment arm?

Answers

Yes. Only a perpendicular component produces a torque.

The Torque is only produced when the force is applied perpendicular to the moment arm.

What is moment of force?

The equal and opposite force acting at a point from the axis of rotation is called the moment.

M = F x r

Moment of force is also called as Torque.

Moment arm is the distance of the point of application of force from the axis of rotation of the body.

Thus, the perpendicular component only, produces the torque.

Learn more about moment of force.

https://brainly.com/question/6278006

#SPJ2

Sí un auto viaja a 8m/s determine Tiempo en llegar a 200km de distancia Distancia que recorre en 40 minutos

Answers

Answer:

a. Tiempo = 25000 segundos

b. Distancia = 19200 metros

Explanation:

Dados los siguientes datos;

Velocidad = 8 m/s

Distancia = 200 km a metros = 200 * 1000 = 200,000

Para encontrar el tiempo para cubrir la distancia anterior;

Tiempo = distancia/velocidad

Tiempo = 200000/8

Tiempo = 25000 segundos

b. Para encontrar la distancia recorrida en 40 minutos;

Tiempo = 40 minutos a segundos = 40 * 60 = 2400 segundos

Distancia = velocidad * tiempo

Distancia = 8 * 2400

Distancia = 19200 metros

If mass is the amount of MATTER present in the
object, will it be different on Earth and the moon?
No
Yes

Answers

Answer:

Yes it would be different on Earth and the moon

Answer:

yes

Explanation:

(a) What is the escape speed on a spherical asteroid whose radius is 301 km and whose gravitational acceleration at the surface is 0.412 m/s2

Answers

Answer:

[tex]V.E=498.02m/s^2[/tex]

Explanation:

From the question we are told that:

Radius [tex]r=301Km[/tex]

Gravitational acceleration [tex]g=0.412 m/s^2[/tex]

Generally the equation for Escape velocity is mathematically given by

 [tex]V.E^2=2gr[/tex]

 [tex]V.E^2=2*0.412m/s^2*301000[/tex]

 [tex]V.E^2=248024[/tex]

 [tex]V.E=\sqrt{248024}[/tex]

 [tex]V.E=498.02m/s^2[/tex]

A dog wishes to swim across a slow moving stream. The current velocity is 3.0m/s. The distance directly across the stream is 50m. If the dog point himself directly across the stream, it will take .....

Answers

Answer:

Time = 16.667 seconds

Explanation:

Given the following data;

Distance = 50 meters

Velocity = 3 m/s

To find the time it will take;

Velocity can be defined as the rate of change in displacement (distance) with time. Velocity is a vector quantity and as such it has both magnitude and direction.

Mathematically, velocity is given by the equation;

Velocity = distance/time

Making time the subject of formula, we have;

Time = distance/velocity

Time = 50/3

Time = 16.667 seconds

help help help please please​

Answers

Answer:

below

Explanation:

that is the procedure above

Mean diameter of cylinder measured by A is 2.50 cm with a possible error of 0.25 cm whereas mean height of cylinder measured by B is 10.0 cm with a possible error of 0.5 cm. Whose measurement is more accurate?

Answers

Answer:

The measurement of first cylinder is more accurate.(A)

Explanation:

The least possible error higher will be accuracy.

The weight of a body is 600 N. What is the mass of the body on the surface of the earth?​

Answers

Explanation:

soln,

weight=600N

mass=?

gravity=9.8 m/s²

now,

mass=weight/gravitymass=600/9.8mass=61.22kg

hope it helps.

stay safe healthy and happy.

Answer:

m = 61.22 kg

Explanation:

F = 600 N

g = 9.8 m/s²

m = ?

F = mg

600 = m(9.8)

---> m = 61.22 kg

physics class 9 chapter 8 please tell​ please

Answers

Answer:

(a) The motion is uniform

(b)  11.11 m/s

Explanation:

(a)

From the table below, the motion of the bus is uniform.

(b)

Speed(s) = Δd/Δt

s = Δd/Δt............. Equation 1

From the table,

Given: Δd = 10 km = 10000 m, Δt = 15 minutes = (15×60) = 900 seconds

Substitute these values into equation 1

s = 10000/900

s = 11.11 m/s

What is the size of the force acting on a copper wire with a magnetic flux density of 3.6 x 10-2 T acting at
right angles to the wire of length 24 m and current of C:048 A? Give your answer to an appropriate
number of significant figures.

Answers

Answer:

F = 0.414 N

Explanation:

Given that,

Magnetic flux density,[tex]B=3.6\times 10^{-2}\ T[/tex]

The length of the wire, l = 24 m

Current, I = 0.48 A

We need to find the force acting on the wire. The formula for the force is given by:

[tex]F=ILB[/tex]

Put all the values,

[tex]F=0.48\times 24\times 3.6\times 10^{-2}\\\\F=0.414\ N[/tex]

So, the force acting on the copper wire is equal to 0.414 N.

The magnetic force of the copper wire is  41.472 N.

Magnetic force of the copper wire

The magnetic force of the copper wire is calculated by applying the following equation.

F = BIL x sinθ

Where;

θ is the inclination of the magnetic fieldI is the currentL is the length of the wireB is the magnetic field strength = flux density

F = (3.6 x 10⁻²) x (48) x 24 x sin(90)

F = 41.472 N

Thus, the magnetic force of the copper wire is  41.472 N.

Learn more about magnetic force here:  https://brainly.com/question/13277365

¿Cuántos electrones por segundo pasan a través de una sección de alambre que lleva una corriente de 0.70 A.?

Answers

Answer:

The number of electrons flowing per second is [tex]4.375\times 10^{18}[/tex].

Explanation:

How many electrons per second pass through a section of wire that carries a current of 0.70 A.?

Current, I = 0.7 A

time, t = 1 s

According to the definition of current, let the charge is q.

q = I t

q = 0.7 x 1 = 0.7 C

Let the number of electrons is n.

[tex]n =\frac{q}{e}\\\\n = \frac{0.7}{1.6\times 10^{-19}}\\\\n = 4.375\times 10^{18}[/tex]

Which two factors affect the size of the gravitational field?

Answers

Answer:

Explanation:

mass and distance

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