# Momentum equation

3 problems and solutions about Momentum equation

1. If the object’s speed becomes 5 times its original speed, then the object’s momentum becomes ….. its original momentum.

Known:

Initial speed = v

Final speed = 5v

Mass = 1

Wanted: Momentum

Solution:

Momentum formula

p = m v = 1 (5) = 5

If the speed is 5 times the original and the mass is constant then the momentum is 5 times the original.

2. An object is thrown upwards on a smooth inclined plane with an initial speed of 10 m/s. The angle of inclination of the plane to the horizontal is 30o. If g = 10 m/s2, then if the mass of the object is 2 kg, the momentum of the object after 1 second is…

Known:

Initial velocity (vo) = 10 m/s

Angle = 30o

Acceleration due to gravity (g) = 10 m/s2

Mass (m) = 2 kg

Wanted: Momentum (p)

Solution:

Momentum Formula

P = m v = (2 kg)(10 m/s) = 20 kg m/s

Momentum is not depend on weight (w = mg).

3. A bullet is fired with a speed of 10 m/s. If the mass of the bullet is 20 grams, calculate the momentum of the bullet.

Known:

Bullet mass (m) = 20 grams = 20/1000 kg = 0.02 kg

Speed (v) = 10 m/s

Wanted: Momentum (p)

Solution:

Momentum formula

p = m v = (0,02 kg)(10 m/s) = 0,2 kg m/s