Question

A body of mass 5 kg is thrown vertically upwards with an initial velocity of 50 m/s.Calculate its kinetic energy . (i)when it half the way (ii)at t=3 sec

Answer 1

Answer:

If u = 50 m/s

Hmax = u² / 2g

          = 2500 / 20

          = 125 m

Half way up would mean H / 2 or 125 / 2

velocity at 125 / 2 is given as ,

v² = u² + 2gh

    = 2500 - 20×125 / 2

    = 2500 - 1250

    = 1250

v = √1250

  = 25√2

KE = 1/2 mv²

     = 1/2×5×25√2×25√2

     = 3125

B )  at t=3 ,

v = u+at

v = 50-30

  = 20 m/s

KE = 1/2 mv²

     = 1/2×5×400

     = 5×200

      = 1000

hope it helped and please mark as brainliest:)