Question

A young hockey player stands at rest on the ice holding a 1.3-kg helmet. The player tosses the helmet directly in front of him with a speed of 6.0 m/s and recoils with a speed of 0.25 m/s .

Answer 1

Through the conservation of momentum principle for an inelastic collision, we can calculate the recoil velocity of a 70.0-kg ice hockey goalie who catches a 0.150-kg hockey puck moving at 35 m/s.

Step-by-step explanation:

The question is related to the subject of Physics, specifically within the domain of mechanics, dealing with the concept of conservation of momentum in inelastic collisions. The scenario describes a situation where a 70.0-kg ice hockey goalie, initially at rest, catches a 0.150-kg hockey puck moving at 35 m/s. Assuming an inelastic collision, where the puck sticks to the goalie, and with friction between the ice and the puck-goalie system being negligible, we can use the principles of conservation of momentum to find the recoil velocity of the goalie. The initial momentum of the system is the momentum of the puck because the goalie is at rest, which is mpuck × vpuck. After the collision, the total momentum is shared between the puck and the goalie now moving together.

The conservation of momentum equation is given by:

mpuck × vpuck, initial = (mgoalie + mpuck) × vfinal

To find the final velocity of the goalie and puck together, we rearrange the equation:

vfinal = × mpuck × vpuck, initial / (mgoalie + mpuck)

By plugging in the known values:

vfinal = (0.150 kg × 35 m/s) / (70.0 kg + 0.150 kg)

The calculated velocity will represent the recoil velocity of the system consisting of both the puck and the goalie.

Answer 2

given,

initial speed of hockey player= 0 m/s

mass of the helmet, m = 1.3 Kg

initial speed of the helmet, u = 0 m/s

final speed of the helmet, v = 6 m/s

recoil speed of the hockey player, v' = 0.25 m/s

we need to calculate the mass of the hockey player, M = ?

using conservation of momentum

m u + M u' = M v' + m v

initial speed of ice skater is zero

1.3 x 0 + M x 0 = M x (-0.25) + 1.3 x 6

negative sign is taken because recoil velocity is in opposite direction

0 = -0.25 M + 7.8

0.25 M = 7.8

M = 31.2 Kg

Hence, the mass of the young hockey player is equal to 31.2 Kg