Question

A boy mass 50kg has a momentum of 300kg m/s. Calculate​

Answer 1

Answer: (1)m = 50 kg, p = 3000 kg ms-1  

Since  p = mv

∴  v = p/m = 3000/50 = 60ms-1  

Kinetic energy of the body = 1/2mv2  

= 1/2 x 50 x (60)2 = 25 x 3600

= 90000 J

(2) Velocity of the body v = 60 ms^-1

Answer 2

Question (Corrected): A boy of mass 50 kg has a momentum of 300 kg m/s. Calculate the velocity of the body at that time.

Solution:-

Mass of the boy (m) = 50 kg

Momentum of the boy (p) = 300 kg m/s

Let the velocity of the boy be = v

We know,

$p = mv$

where,

• p = Momentum,
• m = Mass &
• v = Velocity.

$\therefore v = \frac{p}{m}$

$\implies v = \frac{300 \ kg \ m/s}{50 \ kg}$

$\implies v = 6 m/s$

Final Answer:-

$\bf{\therefore The \ boy \ had \ a \ velocity \ of \ 6 m/s.}$