Question

An 84 kg hockey player skating at 10 m/s to the right collides with another 64 kg player who is standing still. If both players get tangled together during the collision, what is their combined speed?

Answer 1

When a 84 kg hockey player collides with a stationary 64 kg player, they stick together and move as one after the collision. Using the principle of conservation of momentum, their combined velocity can be calculated as 5.68 m/s.

Step-by-step explanation:

When the 84 kg hockey player collides with the 64 kg player who is standing still, the collision is an example of an inelastic collision. In an inelastic collision, the two objects stick together and move as one after the collision. To find their combined speed, we can use the principle of conservation of momentum.

Before the collision, the first player has a momentum of (mass of first player x initial velocity of first player) + (mass of second player x initial velocity of second player) = (84 kg x 10 m/s) + (64 kg x 0 m/s) = 840 kg·m/s.

After the collision, the combined mass of the players is (mass of first player + mass of second player) = 84 kg + 64 kg = 148 kg. Using the principle of conservation of momentum, the final momentum of the combined players is equal to their initial momentum: combined mass x final velocity = 840 kg·m/s. Rearranging the equation, we find that the final velocity of the combined players is 840 kg·m/s ÷ 148 kg = 5.68 m/s.