Question

A blue puck has a velocity of 3i –4j m/s. Its mass is 20 kg. What is its momentum?

Answer 1

Magnitude:

√(3² + 4²) = √(9 + 16) = √25 = 5

Momentum = (mass) x (velocity) = (20kg x 5m/s) = 100 kg-m/s


Direction:

3i - 4j is in the direction tan⁻¹(-4/3) = 53.1 south of east.

Answer 2

P = m * v
v = {3i - 4j} = square root (3^2 + 4^2) = 5
P = 20 * 5
P = 100 kg m/s