Question

A rock is dropped from a high bridge.After 3 seconds of free fall the speed of rock is;
og 4 ms-1

b) 29.4 km s-1
c) 2940 cms-1​

Answer 1

Answer:

c) 2940 cm/s

Explanation:

Given:

Initial velocity (u) = 0 m/s (As it was dropped from rest)

Time (t) = 3 seconds

Acceleration (a) = g = 9.8 m/s²

To find:

Final velocity (v)

Method to find:

v = u + at

⇒ v = 0 + (3 * 9.8)

⇒ v = 29.4 m/s = 2940 cm/s

Hence, the speed of the rock after 3 seconds of free fall was 2940 cm/s.