A ball with a mass of 2 kg rolls on a flat surface. It starts rolling with an initial velocity of 2 m/s, and after a while, its velocity drops to 1.8 m/s. What is the final energy of the ball? a. 1.8 J
b. 4 J
c. 3.24 J
d. 2 J

Which of the following is a true statement about the acceleration ~a of the pendulum bob ~a is equal to the acceleration due to gravity. ~a is perpendicular to the bob’s trajectory. ~a is equal to the instantaneous rate of change in velocity. ~a is tangent to the bob’s trajectory.