Question

65. The momentum of a moving object of mass 100 gm is 100 kg m/s. The
kinetic energy of the object in kilojoules is : Soko
(a) 12500
(b) 0.0125
(c) 12.5
(d) 1:25
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Answer 1

Explanation:

let momentum p = 100 kg m/s

let m be the mass = 100gm = 0.1kg (1 g = 1/1000kg)

now kinetic energy K = 1/2*m*v^2

we know that momentum p = m*v

now v = p/m = 100/0.1 = 1000m/s = 1km/s

now, k = 1/2m*v^2

= 1/2* p * v ( p = m*v)

= 1/2*100*1

= 50kJ (1kJ = 1kg m/s)

But I think options are wrong, since I tried multiple times but answer is coming 50. please recheck it and correct me if iam wrong.

hope u understood it.