A ball rolls downhill with a constant acceleration of 4 m/s2. If it started from rest, its velocity at the end of 3 meters is__

6. A ball is thrown upward with a velocity of 4.5 m/s. Its speed and the magnitude of its acceleration at the highest point (a) are both equal to zero (b) are given by 9.81 m/s and 0 m/s², respectively (c) are given by 0 m/s and 9.81 m/s², respectively (d) cannot be predicted unless the height is known Answer: 7. Which of the following statements about a projectile is not true? Assume that the air resistance is negligible. (a) Its motion is in two dimensions. (b) The only acceleration is in the vertical direction. (c) Its velocity in the horizontal direction remains the same throughout the flight. (d) The velocity at the highest point of its trajectory is zero. Answer:

9. Figure 2 below shows the velocity of a particle as a function of time. (a) Find the acceleration for the five one-second periods and plot the acceleration as a function of time. (b) Taking x = 0 at t = 0, find the position of the particle at t 0.5 s, t = 1.0 s, t = 2.0 s, t = 3.0 s, t = 4.0 s, and t 5.0 s and plot the position as a function of time. Look at the slopes of your x vs t curve for the five one-second periods and show that they correspond to the velocities of Fig. 2. 15.0- 10.0 5.0 0.50 1.00 1.50 2.00 2.30 S.00 350 4.50 3.00 -5.0t -ם.םו- Fig 2 -15.0

A cheetah can accelerate from rest to a speed of 25.5 m/s in 5.00 s. What is its acceleration (in m/s2)? (Enter a number.)

6. A car, starting from rest, accelerates in a straight-line path at a constant rate of 2.5 m/s2. How far will the car travel in 12 seconds? (A) 4.8 m (B) 30 m (C) 120 m (D) 180 m time of