Question

a body is projected vertically upward with speed 55m/s . acceleration due to gravity is 10m/s^2 . displacement of the body in the sixth second of its motion is...
a)zero
b)2.5m
c)5m
d)7.5m

Answer 1

Answer:

Zero

Explanation:

Lets look at the time taken by the body to reach its highest point

using v = u + at

0 = 55 - 10t

t = 55/10 = 5.5s

if you properly understand the situation in the 6th second first half of the 5 - 5.5s it is going up and next half 5.5- 6s its coming down.

by symmetry you can deduce that in that 6th it went up h and came down h so total displacement is zero.

Answer 2

(a) The acceleration due to gravity on the moon is about one-sixth of that on the earth. (b) In order to the force of gravitation between two bodies to become noticeable and cause motion, one of the bodies must have an extremely large mass.