Question

Standing on a friction-less ice surface, ask a skater of mass 70kg fires from his rifle of mass 5kg .A saresult,the skater starts moving in the opposite direction with velocity 2 cm .s-1.If the bullet moves with Velocity 20m.s-1 ,find its mass.

Answer 1

Answer:

75 g

Explanation:

Total mass of rifle and skater (m1) = 75 kg

Velocity of combined mass (v1) = -0.02m/s

Initial velocity of the system = 0m/s = u

Let mass of bullet = m2

Velocity of bullet (v2) = 20m/s

According to conservation of linear momentum,

(m1+m2) u = m1v1 + m2v2

0 = -1.5 kgm/s + 20m2

M2 = 1.5/20 kg = 75 g