A ball is dropped from a rooftop of a building and falls for two seconds. The acceleration of gravity is 9.8 m/s 2 . The ball is referred to at the two-second time. The velocity of the ball in m/s is
A) 0.
B) 4.9.
C) 9.8.
D) 19.6.
E) none of these.

Question

A ball is dropped from a rooftop of a building and falls for two seconds. The acceleration of gravity is 9.8 m/s 2 . The ball is referred to at the two-second time.  The velocity of the ball in m/s is
A) 0.
B) 4.9.
C) 9.8.
D) 19.6.
E) none of these.

Quizplus · Accepted Answer

The velocity of the ball after two seconds can be calculated using the formula v = u + at, where v is the final velocity, u is the initial velocity (which is 0 in this case), a is the acceleration due to gravity and t is the time taken. Substituting the given values, we get v = 0 + (9.8 m/s^2) x 2 seconds = 19.6 m/s. Therefore, the answer is (D) 19.6.

A Ball Is Dropped from a Rooftop of a Building