PHYS 101

Newton’s second law

Example 1

A sled with a mass of 20kg slides along frictionless ice at 4.5 m/s. It then crosses a rough patch of snow that exerts a friction force of f = 12 N (kinetic or static?).

How far does the sled slide before it comes to rest?

Example 2

Students help you move into you dorm and push your boxes up a 20° slope with a horizontal force.How hard do they have to push to get the box moving?Could they make their lives a bit easier?

mass vs. weight

• Moon Olympics

note: John Young’s weight is still stated as 300 pounds …