Question

2.) A stone deropped from the bridge hits
water after 2 seconds. If acceleration of the
stone is 9.8 ms2 then height of the
bridge is
1. 4.9m
2. 9.8m
3. 19.6m
4. 39.2m​

Answer 1

Given,

Time (t) = 2 s

Acceleration due to gravity (g) = 9.8 m/s²

Initial Velocity (u) = 0 m/s

h = ut+0.5gt²

... where h is the height of the bridge,

= (0*2) + (0.5*9.8*2*2)

= 19.6 m

The Height of the Bridge is 19.6 m.

Hope this helps!

Answer 2

Answer:

When particle is dropped from bridge the initial velocity u is zero.

Let the height of bridge from water level is h then the displacement traveled by particle is h.

Acceleration is g downward.

Then applying equation of motion:

Therefore, the correct option is 4.9m