A ball of mass 2.0 kg is thrown vertically upward front the top of a building. The ball’s velocity v is given as a function of time t by the equation v(t)=R-St, where R=5 m/s and s=10 m/s^2. The positive direction is upward. What is the ball’s acceleration at time t= 1 s A. -10 m/s ^2
B. -5 m/s ^2
C. 0
D. 5 m/s^2
E. 10 m/s^2