In an athletic-meet an athlete has to throw a shot put with mass 10 kg with an initial velocity 1 ms at an angle `45^(@)` with the horizontal from a platform 1.5 m above the ground. What will be the kinetic energy of this shot put when it just strikes the ground. Assume the air resistance to be negligible and take the value of 'g' to be 10 ms?

Options

A. 5.0 J
B. 55.0 J
C. 105 J
D. 155 J

Answer

d

Explanation

Here initial K.E. of throw
`E_k=1/2mv^2=1/2xx10xx(1)^2`
`:.` K.E. of strike at the same level `E_k=5J`
Now P.E. at the height 1.5 m
`E_P=mgh=10xx10xx1.5`
=150 J
Total energy of final strike
=150+5=155 J.