Directions: Solve the following problems.

1. A car in front of the school goes from rest to 27 m/s in 3.0 seconds. What is its acceleration (assuming it is constant)?

2. A rocket starts from rest and accelerates at a uniform rate of 190 m/s² for 2.4 seconds. What is its final velocity?

3. A car has a velocity of 15 m/s. It then accelerates at a uniform rate of 3.5 m/s² for the next 5.0 seconds. What distance does the car cover during this time?

4. What distance is required for a train to stop if its initial velocity is 23 m/s and its deceleration is 0.25 m/s²? (Assume the train decelerates at a constant rate.)

5. What distance will a car cover while uniformly accelerating from12 m/s to 26 m/s in 14 seconds?

6. A person starts at rest and accelerates at a uniform rate of 3.2 m/s² for 3.0 seconds. What distance does this person cover in that time?

7. What must be the acceleration of a train in order for it to stop from 12 m/s in a distance of 541 m? (Assume the train accelerates uniformly.)

8. A car will skid to a halt at a uniform rate of -9.4 m/s². If you measure skid marks that are 34 m long, with what speed was the car going just before the driver slammed the brakes?

9. An airplane touches down at a speed of 55.0 m/s on a runway that is 600. m long. The plane can decelerate at a uniform rate of 2.50 m/s². Will the plane be able to stop before the end of the runway?

10. A cyclist is riding along at a constant velocity of 15 m/s. He then accelerates at a uniform rate of 0.50 m/s² over a distance of 64 m. How long did he accelerate?

11. When a driver hits the brakes, his car decelerates at a uniform rate of 2.0 m/s. His car stops at 9.0 m. How long does it take him to stop?

12. A train can speed up at a uniform rate of 0.15 m/s². In what minimum distance can it attain a speed of 25 m/s if it is starting from rest?

13. A drag racer can reach a speed of 53 m/s over a distance of 120 m. Over what distance can it reach a speed of 85 m/s?

Practice Activity 2

Directions: These problems are straightforward kinematics problems. Use the problem-solving process to describe the situations and solve, showing all work. Use g = 10 m/s².

1. With a cruising speed of 128 m/s, the French supersonic passenger jet Concorde is the fastest commercial airplane. Suppose the landing speed of the Concorde is 20.0 percent of the cruising speed, 25.6 m/s. If the plane accelerates at -5.80 m/s², how far does it travel between the time it lands and the time it comes to a complete stop?

2. The first permanent public railway was built by George Stephenson and opened in Cleveland, Ohio, in 1825. The average speed of the trains was 6.6 m/s. Suppose a train moving at this speed accelerates -0.20 m/s² until it reaches a speed of 2.2 m/s. How long does it take the train to undergo this change in speed?

3. Peter Rosendahl rode his unicycle a distance of 100 m in 12.11 s. If Rosendahl started at rest, what was the magnitude of his acceleration?

4. Sam slides down a flagpole which is 20 m high, starting at rest. If he accelerates at a rate of 3 m/s², how long will it take to get to the ground? (3.7 s)

5. Brad is running down the basketball court starting at 10 m/s. If the basket is 5 m away, and it takes him 5 s to get there, what is his acceleration? (-3.6 m/s²)

6. The velocity of a car decreases as it travels down a hill that points down and to the left. Initially, it travels at speed of 9.0 m/s, and 20 m further down the hill the car's speed is 4.0 m/s. Determine the acceleration of the car.(-1.6 m/s²)

7. A car accelerates from 15 m/s to 30 m/s in 4.0 s. How far did the car travel? (90 m)

8. An automobile that set the world record for acceleration increased speed from rest to 27 m/s in 3.07 s. How far had the car traveled by the time the final speed was achieved?

Review

Directions: Answer each of the following questions.

1. A train accelerates from rest with an acceleration of 4 m/s² for a time of 20 s. What is the train's speed at the end of 20 s?

2. A ball is thrown straight upward with a speed of +12 m/s. What is the ball's acceleration just after it is thrown?

3. A bus starting from a speed of +24 m/s slows to 6 m/s in a time of 3 s. What is the average acceleration of the bus?

4. What property does this describe? The length of movement from beginning to end, a vector quantity.

5. What is a scalar quantity?

6. How long will it take for a car to slow down from 22 m/s to 3 m/s if it decelerates at 2.4 m/s/s?

7. Acceleration describes a change in _____.

8. A ball is thrown straight upward with a speed of +12 m/s. How much time does it take for the ball to rise to its maximum height?

9. What kind of quantity is the distance?

10. What is a good statement for velocity?

11. A football player starts from rest 10 meters from the goal line and accelerates away from the goal line at 5 m/s². How far from the goal line is the player after 4 s?

12. Describe acceleration.

13. What is a scalar measurement?