At the edge of a roof you drop ball A from rest and then thr

At the edge of a roof you drop ball A from rest, and then throw ball B downward with an initial velocity of v0. Suppose the balls are released at the same time. (Figure 1)

A: Identify which of the 5 plots shown (1,2,3,4 or 5) in the figure corresponds to ball A.

B: Identify which of the 5 plots shown (1,2,3,4 or 5) in the figure corresponds to ball B.

Solution

when Ball A drops , its velocity after time t

V_A = U_A+gt =0+9.81*t =9.81t

Velocity of Ball A after time t is directly proportional to time hence it is a straight line passing through origin.

Figure 3 corresponds to Ball A.

V_B= U_B +g*t = V_o + 9.81*t

Figure 2 corresponds to Ball B