Question

1. Over a time interval of 2.20 years, the velocity of a planet orbiting a distant star reverses direction, changing from +23.7 km/s to -24.2 km/s. Find (a) the total change in the planet's velocity (in m/s) and (b) its average acceleration (in m/s²) during this interval. Include the correct algebraic sign with your answers to convey the directions of the velocity and the acceleration.

2.  A car is traveling at a constant speed of 27.2 m/s on a highway. At the instant this car passes an entrance ramp, a second car enters the highway from the ramp. The second car starts from rest and has a constant acceleration. What acceleration must it maintain, so that the two cars meet for the first time at the next exit, which is 2.93 km away?

3. You are driving your car, and the traffic light ahead turns red. You apply the brakes for 2.53 s, and the velocity of the car decreases to + 4.81 m/s. The car’s deceleration has a magnitude of 2.96 m/s² during this time. What is the car’s displacement?

4. A ball is thrown straight upward and rises to a maximum height of 17.6 m above its launch point. At what height above its launch point has the speed of the ball decreased to one-half of its initial value?

5.A diver springs upward with an initial speed of 1.88 m/s from a 3.0-m board. (a) Find the velocity with which he strikes the water. [Hint: When the diver reaches the water, his displacement is y = -3.0 m (measured from the board), assuming that the downward direction is chosen as the negative direction.] (b) What is the highest point he reaches above the water?

Answer 1