A heavy ball falls freely, starting from rest.Between the third and fourth second of its fall it travels a distance of:
A)4.9 m.
B)9.8 m.
C)29.4 m
D)34.3 m.
E)39.8 m.

Question

Quizplus · Accepted Answer

We know that the distance traveled by a freely falling object is given by:

d = (1/2)gt^2

where d is the distance, g is the acceleration due to gravity, and t is the time.

Between the third and fourth second, the time interval is 1 second. Therefore, we can calculate:

d = (1/2)g(4^2) - (1/2)g(3^2) 
d = (1/2)(9.8 m/s^2)(16 - 9) 
d = (1/2)(9.8 m/s^2)(7) 
d = 34.3 m

Therefore, the best choice is D.

A Heavy Ball Falls Freely, Starting from Rest