What is the direction of the acceleration vector for each of these situations? Remember that if an object speeds up, then the velocity and acceleration vectors are in the same direction. If an object slows down, then they are in opposite directions. Any object that is traveling in a vertical direction also experiences acceleration due to gravity. Left: Object travels to left and speeds up. Down: Object is tossed upward. A ball is tossed up into the air with a velocity of 50 m/s.

The figure to the left shows the position of the ball at equal time intervals on its upward travel. Answer the following questions regarding the instantaneous velocity and acceleration of the ball: True: The velocity of the ball has decreased from point B to point C. Point C: Where does the ball have the smallest velocity? Down: What is the direction of acceleration of the ball at point B? True: The acceleration points downwards at point C. A ball is thrown upward at time t = 0 s from the ground with an initial velocity of 4 m/s (~ 9 mph).

Assume that g = 10 m/s2. At what time t does the ball reach its apex (highest point)? 0. 4000 s At what time t does the ball reach the ground? 0. 8000 s What is the maximum height (apex) reached by the ball? 0. 8000 m Correct: The ball has a positive acceleration when rolling both up and down the ramp. A 1100 kg racing car accelerates from rest at a constant rate and covers a distance of 1000 m in 20 s. What is the car’s acceleration? 5 m/s2