Chemistry: A car traveling at 30 m/s comes to a stop in 5 seconds. What is the acceleration of this car?

A car traveling at 30 m/s comes to a stop in, №13197728, 17.01.2021 23:35

Mathematics

Avehicle accelerates from 0 to 30 m/s in 10 seconds on a straight road, then travels 15 seconds at a constant velocity. Next it slows down, coming to a stop in 5 seconds. The car waits 10 seconds, and then backs up for 5 seconds accelerating from 0 to -10 m/s. Draw a graph showing the vehicle s velocity vs time by following these steps. What is the velocity of the vehicle at 0 seconds? v m/s

Step-by-step answer

P Answered by Specialist

5

The velocity of the vehicle at 0 s is 0 m/s

Explanation:

The Velocity vs. Time graph of this situation is shown in the attached image. As we can see, we have five segments:

1) When the vehicle accelerates from 0 to 30 m/s in 10 seconds, which means at 0 seconds the vehicle's velocity was 0 m/s. In addition, as the vehicle goes from zero to a positive velocity, we have a positive slope.

2) Then the vehicle travels for 15 seconds at a constant velocity, that is why we do not have a slope in this section, since the vehicle kept its 30 m/s.

3) The vehicle comes to a stop in the next 5 seconds, that is why we observe an abrupt change in the graph and a negative slope.

4) The car waits 10 seconds in that stop, again we have a line with no slope

5) Finally, the car accelerates from 0 to -10 m/s in the next 5 seconds. This means the car changed its direction.

Physics

Avehicle accelerates from 0 to 30 m/s in 10 seconds on a straight road, then travels 15 seconds at a constant velocity next it slows down, coming to a stop in 5 seconds. the car waits 10 seconds, and then backs up for 5 seconds accelerating from 0 to -10 m/s draw a graph showing the vehicle s velocity vs time by following these steps what is the velocity of the vehicle at 0 seconds? m/s

Step-by-step answer

P Answered by PhD

40

The velocity of the vechicle at 0 s is 0 m/s

Explanation:

The Velocity vs. Time graph of this situation is shown in the attached image. As we can see, we have five segments:

1) When the vehicle accelerates from 0 to 30 m/s in 10 seconds, which means at 0 seconds the vehicle's velocity was 0 m/s. In addition, as the vehicle goes from zero to a positive velocity, we have a positive slope.

2) Then the vehicle travels for 15 seconds at a constant velocity, that is why we do not have a slope in this section, since the vehicle kept its 30 m/s.

3) The vehicle comes to a stop in the next 5 seconds, that is why we observe an abrupt change in the graph and a negative slope.

4) The car waits 10 seconds in that stop, again we have a line with no slope

5) Finally, the car accelerates from 0 to -10 m/s in the next 5 seconds. This means the car changed its direction.

Mathematics

Avehicle accelerates from 0 to 30 m/s in 10 seconds on a straight road, then travels 15 seconds at a constant velocity. Next it slows down, coming to a stop in 5 seconds. The car waits 10 seconds, and then backs up for 5 seconds accelerating from 0 to -10 m/s. Draw a graph showing the vehicle s velocity vs time by following these steps. What is the velocity of the vehicle at 0 seconds? v m/s

Step-by-step answer

P Answered by Specialist

5

The velocity of the vehicle at 0 s is 0 m/s

Explanation:

The Velocity vs. Time graph of this situation is shown in the attached image. As we can see, we have five segments:

1) When the vehicle accelerates from 0 to 30 m/s in 10 seconds, which means at 0 seconds the vehicle's velocity was 0 m/s. In addition, as the vehicle goes from zero to a positive velocity, we have a positive slope.

2) Then the vehicle travels for 15 seconds at a constant velocity, that is why we do not have a slope in this section, since the vehicle kept its 30 m/s.

3) The vehicle comes to a stop in the next 5 seconds, that is why we observe an abrupt change in the graph and a negative slope.

4) The car waits 10 seconds in that stop, again we have a line with no slope

5) Finally, the car accelerates from 0 to -10 m/s in the next 5 seconds. This means the car changed its direction.

Physics

Avehicle accelerates from 0 to 30 m/s in 10 seconds on a straight road, then travels 15 seconds at a constant velocity next it slows down, coming to a stop in 5 seconds. the car waits 10 seconds, and then backs up for 5 seconds accelerating from 0 to -10 m/s draw a graph showing the vehicle s velocity vs time by following these steps what is the velocity of the vehicle at 0 seconds? m/s

Step-by-step answer

P Answered by PhD

40

The velocity of the vechicle at 0 s is 0 m/s

Explanation:

The Velocity vs. Time graph of this situation is shown in the attached image. As we can see, we have five segments:

1) When the vehicle accelerates from 0 to 30 m/s in 10 seconds, which means at 0 seconds the vehicle's velocity was 0 m/s. In addition, as the vehicle goes from zero to a positive velocity, we have a positive slope.

2) Then the vehicle travels for 15 seconds at a constant velocity, that is why we do not have a slope in this section, since the vehicle kept its 30 m/s.

3) The vehicle comes to a stop in the next 5 seconds, that is why we observe an abrupt change in the graph and a negative slope.

4) The car waits 10 seconds in that stop, again we have a line with no slope

5) Finally, the car accelerates from 0 to -10 m/s in the next 5 seconds. This means the car changed its direction.

Physics

5. a race car has a mass of 710 kg. it starts from rest and travels 40.0m in 3.0s. the car is uniformly accelerated during the entire time. what net force is acting on the car? 6. suppose that a 1000 kg car is traveling at 25 m/s (≈55 mph). its brakes can apply a force of 5000n. what is the minimum distance required for the car to stop? 7. a 65 kg person dives into the water from the 10 m platform. a) what is her speed as she enters the water? b) she comes to a stop 2.0 m below the surface of the water. what net force was exerted on the swimmer?

Step-by-step answer

P Answered by PhD

1

5. 6319 N

First of all, we need to find the acceleration of the car, which can be found by using the equation

$S=\frac{1}{2}at^2$

where

S = 40.0 m is the distance travelled by the car

t = 3.0 s is the time taken

a is the acceleration

Solving for a, we find

$a=\frac{2S}{t^2}=\frac{2(40.0 m)}{(3.0 s)^2}=8.9 m/s^2$

So now since we know the mass of the car, m=710 kg, we can find the net force acting on the car:

F=ma=(710 kg)(8.9 m/s^2)=6319 N

6. 62.5 m

In this case, we know the breaking force applied on the car,

F=-5000 N

(with a negative sign since its direction is opposite to the car's motion)

and the mass of the car

m=1000 kg

so we can find its acceleration:

$a=\frac{F}{m}=\frac{-5000 N}{1000 kg}=-5 m/s^2$

So now we can find the minimum distance to stop by using the equation

v^2-u^2 = 2ad

where in this case we have

v = 0 m/s is the final speed

u = 25 m/s is the initial speed

a = -5 m/s^2 is the acceleration

d is the distance

solving for d,

$d=\frac{v^2-u^2}{2a}=\frac{0^2-(25 m/s)^2}{2(-5 m/s^2)}=62.5 m$

7a. 14 m/s

We can solve the problem by using the law of conservation of energy: in fact, the initial gravitational potential energy of the person is all converted into kinetic energy as she hits the water below

$mgh=\frac{1}{2}mv^2$

where

m = 65 kg is the mass of the person

g = 9.8 m/s^2

h = 10 m is the initial height of the diver

v is the final speed as she enters the water

Solving for v, we find

$v=\sqrt{2gh}=\sqrt{2(9.8 m/s^2)(10 m)}=14 m/s$

7b. -3185 N

We need to find the acceleration of the diver during the motion of 2.0 m below the water:

v^2-u^2 = 2ad

where

v = 0 is the final speed

u = 14 m/s is the initial speed as she enters the water

a is the acceleration

d = 2.0 m is the distance covered

Solving for a,

$a=\frac{v^2-u^2}{2d}=\frac{0^2-(14 m/s)^2}{2(2.0 m)}=-49 m/s^2$

And so now we can find the net force acting on the diver

F=ma=(65 kg)(-49 m/s^2)=-3185 N

8a. -133 m/s^2

The acceleration of the passenger is given by

$a=\frac{v-u}{t}$

where

v = 0 m/s is the final speed

u = 13.3 m/s is the initial speed

t = 0.10 s is the time interval

Solving for a, we find

$a=\frac{0-13.3 m/s}{0.10 s}=-133 m/s^2$

8b. 3325 N

The force that the driver must exert on the child is equal in magnitude to the force experienced by the child during the stop of the car, so

F=ma

where

m = 25 kg is the mass of the child

a=-133 m/s^2 is the acceleration

So, the magnitude of the force will be

F=(25 kg)(133 m/s^2)=3325 N

8c. 245 N

The weight of the child is given by

W=mg

where

m = 25 kg is the child's mass

g = 9.8 m/s^2 is the acceleration due to gravity

Solving the equation,

W=(25 kg)(9.8 m/s^2)=245 N

8d. 55.1 lb

Since we know that

1 lb = 4.45 N

We can find the weight in pounds by setting the following proportion

1 lb : 4.45 N = x : 245 N

Solving for x,

$x=\frac{(1 lb)(245 N)}{4.45 N}=55.1 lb$

8e. Chances are very low

The force that the driver should exert on the child is

F = 3325 N

This force is equivalent to the force required to lift an object of mass m:

$F=mg\\m=\frac{F}{g}=\frac{3325 N}{9.8 m/s^2}=339.3 kg$

So, it is equivalent to the force required to lift an object of 339.3 kg, which is quite a lot. therefore, the changes are very low.

Chemistry

18. the graph below represents a car’s motion as it accelerates from rest. which of the following graphs best represents the relationship between the accelerating car’s position and time? 1 point captionless image a b c d 19. which of the following examples demonstrates velocity? a. a 10.0 kg object b. a truck that traveled 12.5 m c. a 3.5 kg object moving at 1.5 m/s d. a car moving northeast at 90 km/hr 20. the graph represents the acceleration of two cars, accel 1 and accel 2, during a road trip. which statement best describes the differences

Step-by-step answer

P Answered by PhD

12

19. D. A car moving northeast at 90 km/hr

To answer this question you have to know the difference between velocity and speed. Velocity is the same as speed, but with direction. Option A and option B doesn't even have speed as it don't give a distance per time unit. Option C have speed, but doesn't have direction so it doesn't have velocity.

20. C. Accel 1 has a constant rate of acceleration; Accel 2 accelerates at different rates during the trip.

The velocity graph of Accel 1 is an upward straight line. This show that the velocity keep increasing through the entire trip, so it should have constant positive acceleration the entire trip.

The velocity graph of Accel 2 start with higher upward straight line, but then downward until zero. This show there is a positive acceleration on the first trip, but then become negative at the end. There is a change in the Accel 2 acceleration.

21. C) 200 N right

From the picture, the object has 50N downward force, 50N upward force and 200N force to the right.

The sum of the force in vertical direction would be: 50N- 50N=0N.

The sum of the force in horizontal direction would be: 200N.

The answer will be 200N to the right

22. d) a toy car moving east at a constant velocity

When the net force of an object is greater than zero, the force will be converted into kinetic energy which will increase the velocity the object. This will allow the object to have acceleration. A glass resting and a ladder leaning against a wall doesn't even have velocity. A toy car moving east at a constant velocity, doesn't have acceleration.

23. B. increases.

Gravity cause the object to have potential energy. Gravity force is directly related to the mass and inversely related to the distance square of the object. If the mass increases, then potential energy of the object would be increased too.

24. C. The part will move at a constant speed along a straight path until it is acted upon by another force.

The part get energy from the astronaut force which converted into kinetic energy. As long as the part having kinetic energy, it will continually move. Since the space has no air, there will be no air to stop the part. The part will continue to move at constant speed(no acceleration) until any force bump into it.

25. D. The hockey stick will change the speed of the puck and make it accelerate.

If an object collide with another stationary object, some of the kinetic energy will be transferred. The kinetic energy of the hockey stick will be transferred to the puck, which cause the puck to have acceleration. The hockey stick will lose some energy and become a bit slower because of this.

26. D. For every action your cat makes, there is an equal and opposite reaction from the string.

This case is similar to the previous question. When the cat moving her paw and collide with the toy(action), there will be some force put on both the toy and cat paw. The force will cause the toy accelerate and make it moving away from the cat(reaction) while reducing the kinetic energy of the cat paw.

27 B. They hit each other with the same force in opposite directions.

This will also be explained by Newton's third law of motion. For every action there will be equal opposite reaction. When baseball and bat collide, the action from baseball will cause reaction on the bat and the baseball. The action from the bat also will cause reaction on the bat and the baseball too.