PHYS 2211 Module 9.1

Linear Momentum

9.1 Linear Momentum

By the end of this section, you will be able to:

The linear momentum p of an object is the product of its mass and its velocity:

Practice 9.1.1
A 2.5-kg cart moving to the right (+x direction) with a speed of 12 m/s collides with a concrete wall and rebounds with a speed of 4 m/s. What is the change in momentum of the cart?
(a) 0
(b) −30 kg·m/s
(c) −10 kg·m/s
(d) 40 kg·m/s
(e) −40 kg·m/s

Practice 9.1.2
If two particles have equal momentum, are their kinetic energies equal?
(a) yes, always
(b) no, never
(c) no, except when their masses are equal
(d) yes, as long as they move along parallel lines