Question

a stone is thrown vertically upwards with a velocity of 40 metre per second at what height will its kinetic & potential energy be equal (b) calculate p.e. of the body if its mass is 10kg​

Answer 1

Answer:

Initial velocity (u) = -40 m/s

Final velocity (v) = 0 m/s

Acceleration (g) = -10 m/s2

Therefore distance travelled by it,

2as = v2-u2

 2(-10)(s) = 02 – (-40)2

 -20s = -1600

 s = 1600/20

 s= 80 m

Therefore, distance covered by the body would be = 80 m

(a) at half distance the kinetic energy and the potential energy would be the same  

I.e. in 80/2 = 40 m

In 40 m kinetic and potential energy would be the same.

(b) Mass = 10 kg

Height = 80 m

Acceleration = -10 m/s2

Potential energy = mgh

= 10 . -10 . 80