Answer:
t = 9.14 s
Explanation:
We first analyze the accelerating motion by applying first equation of motion:
Vf₁ = Vi₁ + a₁t₁
where,
Vf₁ = Final Speed of Car before turning off engine
Vi₁ = Initial Speed of Car = 0 m/s
a₁ = acceleration of car = 25 m/s²
t₁ = time taken in accelerating motion
Therefore,
Vf₁ = 25t₁ ---------- equation (1)
Now, we apply second equation of motion:
s₁ = Vi₁ t₁ + (1/2)a₁t₁²
where,
s₁ = distance covered during accelerating motion
Therefore,
s₁ = (0)t₁ + (1/2)(25)t₁²
s₁ = 12.5 t₁² ----------- equation (2)
Now, we analyze the decelerating motion by applying first equation of motion:
Vf₂ = Vi₂ + a₂t₂
where,
Vf₂ = Final Speed of Car = 0 m/s
Vi₂ = Initial Speed of Car after turning off engine
a₂ = deceleration of car = - 3 m/s²
t₂ = time taken in decelerating motion
Therefore,
Vi₂ = 3t₂ ---------- equation (3)
Now, we apply second equation of motion:
s₂ = Vi₂ t₂ + (1/2)a₂t₂²
where,
s₂ = distance covered during decelerating motion
Therefore,
s₂ = (Vi₂)t₂ + (1/2)(-3)t₂²
s₂ = Vi₂ t₂ - 1.5 t₂²
using equation (3):
s₂ = 3 t₂² - 1.5 t₂²
s₂ = 1.5 t₂² ------------ equation (4)
Now, we know that the Final Velocity of accelerating motion (Vf₁) is equal to the initial velocity of decelerating motion (Vi₂):
Vf₁ = Vi₂
using equation (1) and equation (3):
25 t₁ = 3 t₂
t₁ = 0.12 t₂ ------------ equation (5)
Also, we know that sum of the distances is 200 m:
s₁ + s₂ = 200
using equation (2) and equation (4):
12.5 t₁² + 1.5 t₂² = 200
using equation (5):
12.5 (0.12 t₂²) + 1.5 t₂² = 200
3 t₂² = 200
t₂² = 200/3
t₂ = 8.16 s
substitute this in equation (5):
t₁ = 0.12(8.16 s)
t₁ = 0.97 s
Hence, the minimum time required for this motion is:
t = t₁ + t₂ = 0.97 s + 8.16 s
t = 9.14 s
What type of energy is stored in a pendulum at the top of its arc?
Answer:
potential
Explanation:At this point the energy is stored in a form called potential energy. This means that the system has the potential to do work or to become active thanks here to the weight's position high above the lowest point of its swing.
ANSWER QUICK!!
describe two uses for microwave radiation
heat food, warm water
A 2000 kg minivan runs into a 800 kg car that was at rest at a stop sign and they stick together. If the compact car does not stick to the van but, instead, causes the minivan to come to a complete stop. How fast will the car be going after the collision?
Answer:
v₂ = 2.5 v₁
car leaves at 2.5 times the speed of the minivan
Explanation:
This is an exercise of conservation of the momentum, to solve it we create a system formed by the minivan and the car, therefore during the crash the forces are internal and the momentum is conserved.
Initial instant. Before the crash
p₀ = M v₁+ 0
Final moment. After the crash
[tex]p_{f}[/tex] = M 0 + m v₂
how momentum is conserved
p₀ = p_{f}
M v₁ = m v₂
v₂ = [tex]\frac{M}{m}[/tex] v₁
let's calculate
v₂ = 2000/800 v₁
v₂ = 2.5 v₁
therefore the car leaves at 2.5 times the speed of the minivan
A parallel-plate capacitor is constructed using adielectric material whose dielectric constant is 3.00 and whose dielectric strength is 2.00X108V/m. The desired capacitance is 0.250 μF, and the capacitor must withstand a maximum potential difference of 4.00 kV. Find the minimum area of the capacitor plates.
Answer:
A = 0.188 m²
Explanation:
First we find the distance between the plates by using the formula of electric field intensity:
E = ΔV/d
d = ΔV/E
where,
d = distance between plates = ?
ΔV = Potential Difference = 4 KV = 4000 V
E = Electric Field = 2 x 10⁸ V/m
Therefore,
d = 4000 V/(2 x 10⁸ V/m)
d = 2 x 10⁻⁵ m
Now, we find the Area of Plates by using formula of capacitance:
C = A∈₀∈r/d
where,
C = Capacitance = 0.25 μF = 0.25 x 10⁻⁶ F
A = Area of Plates = ?
∈₀ = Permittivity of free space = 8.85 x 10⁻¹² C/N.m²
∈r = Dielectric Constant = 3
Therefore,
0.25 x 10⁻⁶ F = A(8.85 x 10⁻¹² C/N.m²)(3)/(2 x 10⁻⁵ m)
A = (0.25 x 10⁻⁶ F)(2 x 10⁻⁵ m)/(3)(8.85 x 10⁻¹² C/N.m²)
A = 0.188 m²
Sharon is driving on a straight road. She is driving north, and her speed is
decreasing. If north is the positive direction, which of the following
statements is accurate?
A) Her velocity is positive, and her acceleration is negative.
B) Her velocity is negative, and
her acceleration is negative.
C) Her velocity is negative, and her acceleration is positive.
D) Her velocity is positive, and her acceleration is positive.
Plzz help
Answer:
b
Explanation:
b is the correct answer
Answer:
b. Her velocity is positive, and her acceleration is negative.
Explanation:
Which of the following charts correctly compares plant and animal cells?
Answer:
Wheres the charts??
Explanation:
Matter can exist in hw many states
Answer:
Matter can exist in four different states: solids, liquids, gases and plasma.
Explanation:
Hope this helps :)
PLEASE HELP ME! IM TIMED
Answer:
the third one
Explanation:
the 1991 eruption of mt. pinatubo was the scariest in history
Answer:
C
Explanation:
It is based on someone’s experience and how they felt about the accident
A spring has a spring constant of 120 N/m. How much energy is stored in the spring as it is stretched a distance of 0.20 meter?
Answer:
2.4J
Explanation:
Given parameters:
Spring constant = 120N/m
Extension = 0.2m
Unknown:
Amount of energy = ?
Solution:
The energy stored in this stretched spring is called the elastic potential energy.
It can be derived using the expression below:
Elastic Potential energy = [tex]\frac{1}{2}[/tex] ke²
k is the elastic constant
e is the extension
Insert the parameters;
Elastic potential energy = [tex]\frac{1}{2}[/tex] x 120 x 0.2² = 2.4J
What are the two factors affect the weight of an object?
Answer:
mass and distance
Explanation:
hope this helped
Colette launches an air rocket in the upward, positive direction. It launches
with an initial velocity of 25.5 m/s. It accelerates in the downward, negative
direction at a rate of 9.81 m/s2. After 3.5 seconds, what is the magnitude of
the rocket's displacement?
A) 29 meters
B) 31 meters
C) –150 meters
D) 150 meters
Answer:
b
Explanation:
Answer:
The answer is A) 29 meters
Explanation:
I got this question right on the test! :)
How much Tension force is required to pull a 1500 kg car (it is being towed) forward with an acceleration of 3 m/s^2 if the friction force on the towed car's tires is pulling backward with a force of 2500 N?
If the pull is done horizontally, then the net force on the car is
∑ F = T - f = (1500 kg) (3 m/s²)
where T is the magnitude of the tension in the towing cable, and f is the friction which points in the opposite direction. Then
T = f + (1500 kg) (3 m/s²)
T = 2500 N + 4500 N
T = 7000 N
How can you double the acceleration of an object if you cannot alter the object’s mass?
plz helpppp
Answer:
If you double the force, you double the acceleration, but if you double the mass, you cut the acceleration in half.
Explanation:
you can double the net force
Jack jumped off a diving board and hit the water at 15.68 m/s downward. How long was he falling for before he hit the water?
Answer:
1.6 s
Explanation:
From the question given above, the following data were:
Velocity (v) = 15.68 m/s
Acceleration due to gravity (g) = 9.8 m/s²
Time (t) =?
Thus, we can calculate the time taken for Jack to hit the water by using the following formula:
v = gt
15.68 = 9.8 × t
Divide both side by 9.8
t = 15.68 / 9.8
t = 1.6 s
Therefore, it took Jack 1.6 s to hit the water.
a block weighing (Fg) 50 N is resting on a steel table (us = 0.74). The minimum force to start this block moving is what N
Answer:37
Explanation:
A 0.050 kg ball starts from rest at some unknown height on a toy roller coaster.
At a later time, it travels through the top of a loop at 2 m/s and a height of 0.40 m.
Since this track is frictionless, what was the starting height of the ball?
Answer:
The starting height of the ball is approximately 0.604 m
Explanation:
The given parameters are;
The mass of the the ball = 0.050
The speed with which it travels through the top loop = 2 m/s
The given height at which the ball moves at 2 m/s = 0.40 m
Therefore, we have;
1/2·m·v² = m·g·h
1/2·v² = g·h
h = 1/2·v²/g = 1/2 × 2²/9.81 ≈ 0.204
The additional height = h = 0.204 m
Therefore;
The starting height of the ball ≈ The given height at which the ball moves at 2 m/s + h
The starting height of the ball ≈ 0.40 + 0.204 = 0.604 m
The starting height of the ball ≈ 0.604 m.
When any object in rest, then potential energy is present. But when object is in motion then object have kinetic energy.
Starting height of the ball is 0.604 m.
We know that, when any object is start from rest, then potential energy is converted into kinetic energy.
[tex]\frac{1}{2}mv^{2} =mgh[/tex]
Where m is mass of object, g is gravitational acceleration , h is height and v is velocity of object. (value of g = 9.81 m/ second square)
from above equation,
we get, extra height [tex]h=\frac{v^{2} }{2g} \\\\h=\frac{4}{2*9.81}\\\\h=0.204[/tex] meter
The starting height of the ball will be sum of the height at which ball moves 2 m/s and extra height.
Starting height = 0.40 + 0.204 = 0.604 meter.
Learn more:
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A car travels 3500 m in 200 seconds what is the car speed
Answer:
17.5 m/s
Explanation:
We can calculate the meters per second by dividing the distance by time. 3500 divided by 200 is 17.5, therefore the speed is 17.5 meters per second.
Integrated science please help ASAP!...
Answer:
SewageAgricultural pollutionOilRadioactive substanceRiver dumpingMarine dumpingLittering trash Industrial wasteMining activitiesChemical fertilizersExplanation:
I hope this helps
A book that weighs 5 N sits on a table. What force does the table apply to the book?
Answer:
E =F.d =[1/2]mv^2
mad = [1/2]mv^2
d= v^2/2a ,v=u+at , v^2 = [at]^2 since u=0
So d = at^2/2
F = ma= 20a= 50 , a=5/2 and t=2
so d = [5/2][2^2]/2=5
Explanation:
Every action has an equal and opposite reaction. It is an action-reaction principle. Therefore the table exerts a force of 5 N on the book in order to be in stable condition.
What is Newton's third law of motion?Newton's third law of motion state that every action has an equal and opposite reaction. It is an action-reaction principle. It stated that the force always exists in a pair.
Therefore the table exerts a force of 5 N on the book in order to be in stable condition.
The given data in the problem is ;
W is the weight of the book sits on table = 5N
N is the normal force on the book
From the equilibrium equation ;
Weight -Normal force on the book =0
Weight =Normal force on the book
The normal force on the book =5N
Hence the table exerts a force of 5 N on the book in order to be in stable condition.
To learn more about Newton's third law of motion refer to the link;
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Students are asked to design an experiment about Newton’s 2nd Law. One student decides to roll a marble down a ramp into a pile of sand to measure the force impact.
Which variable should she manipulate to best exemplify the relationship explained by this law?
A.She should use a heavier marble, because the marbles will roll at the same rate of acceleration but more mass will produce a larger impact force.
B.She should increase the slope of the ramp by propping it up to higher height, because a steeper ramp will cause a greater rate of acceleration and a larger impact force.
C.She should use a heavier marble, because a bigger marble will accelerate more quickly down the ramp and cause a greater impact force.
D.She should decrease the slope of the ramp, because a ramp with a smaller slope will allow the ball more time to build up speed and cause a greater impact force.
Answer:
A
Explanation:
Trust me I just took it !
When a 0.622 kg basketball hits the floor, its velocity changes from 4.23 m/s down to 3.85 m/s up. If the average force was 72.9 N, how much time was it in contact with the floor?
(Unit = s)
Remember: up is +, down is -
Answer:
t = 0.0689 s
Explanation:
Given that,
Mass of a basketball, m = 0.622 kg
Initial velocity, u = 4.23 m/s (downward or negative)
Final velocity, v = 3.85 m/s (up of positive)
Average force, F = 72.9 N
We need to find the time it was in contact with the floor. The force is given by :
[tex]F=ma\\\\F=m\dfrac{v-u}{t}\\\\t=\dfrac{m(v-u)}{F}\\\\t=\dfrac{0.622\times (3.85-(-4.23))}{72.9}\\\\t=0.0689\ s[/tex]
So, the time of contact is 0.0689 s.
What do scientists hope to learn from missions to visit asteroids?
Answer:
The mission will help scientists investigate how planets formed and how life began, as well as improve our understanding of asteroids that could impact Earth.
Explanation:
Hope this helps :)
HELP ASAP!!!! Ashley and Rachel are driving bumper cars. Ashley's bumper car is moving and she collides with Rachel bumper car, which is not moving. Describe what happens to the momentum of both cars During this collision.
Answer:
Rachels car moves and ashleys stops
Explanation:
When Ashley's moving car collides with Rachel's bumper car which is at rest then some of the momentum of Ashley's car is transferred to Rachel's car causing it to move.
What is the conservation of momentum?Conservation of momentum states that the momentum of a system is constant if there is the absence of external forces on the system. The momentum of an object can be conserved and is a vector quantity.
Momentum can be defined as the multiplication of the mass of a particle and its velocity. The law of conservation of momentum is confirmed by experiment and can be deduced mathematically on the presumption that space is uniform.
Conservation of linear momentum is derived from Newton’s second law of motion states that the total momentum remains the same in an isolated system.
The total momentum of Ashley's car and Rachel's car remains conserved. After the collision, the momentum transferred from Ashley's car and Rachel's car which makes it move.
Learn more about the conservation of momentum, here:
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How much power will it take to move a 10 kg mass at an acceleration of 2 m/s² a distance of 10 meters in 5 seconds?
Answer:
100 Watts
Explanation:
These equations are needed to work out the answer:
power= work done/ time takenwork done= force* distanceforce= mass* accelerationforce: 10 kg* 2m/s= 20
work done: 20* 10m=200
power: 200/2=100
a man hits a golf ball (0.2kg) which accelerates at a rate of 20 m/s/s . what amount of force acted on the ball
Answer:
4 NExplanation:
The force acting on an object given it's mass and acceleration can be found by using the formula
force = mass × acceleration
From the question we have
force = 0.2 × 20
We have the final answer as
4 NHope this helps you
Answer:
The ball only accelerates during the brief time that the club is in contact
with it. After it leaves the club face, it takes off at a constant speed.
If it accelerates at 20 m/s² during the hit, then
Force = (mass) x (acceleration) = (0.2kg) x (20 m/s²) = 4 newtons .
Explanation:
bold completed over 100m in 9.58
seconds what is his average speed
Answer:
At the Berlin 2009 World Championships, Bolt set a world record time of 9.58 seconds for the 100m race, notching a top speed of 27.8 miles per hour (44.72 kilometers per hour) between meters 60 and 80, with an average speed of 23.5 mph.
Explanation:
Jason rides his bicycle for 3 hours at a speed to 40 km/h. What distance does he
travel? -
Answer:
120km
Explanation:
6th grade science I mark as brainliest.
Answer:
2m 13[tex]\frac{1}{3}[/tex]s
Explanation:
1.5m = 1s
200m = [tex]\frac{200}{1.5}[/tex] × 1s
= 133[tex]\frac{1}{3}[/tex]s
= 2m 13[tex]\frac{1}{3}[/tex]s
the strongly blown ballon gets blasted why?
Answer:
Because of pressure.
Thanks
Explanation:
The pressure bursts out the balloo
How should the amount of elastic potential energy when the spring is fully stretched compare to the amount of kinetic energy when the spring is relaxed?
If there are no dissipative forces acting on the string, than the principle of conservation of energy holds.
When the string is relaxed, it has zero elastic potential energy
If we were strech the she spring, we would increase it's potential energy. After releasing the spring, when it's relaxed again, all potential energy will have been converted into kinetic energy.
Therefore, the elastic potential energy of the stretched spring should be equal to the amount of kinetic energy when it's relaxed
