Question

A boy is exerting a force of 70 N at a 50-degree angle on a lawn mower. He is accelerating at 1.8 m/s2. Round the answers to the nearest whole number.
What is the mass of the lawn mower?

What is the normal force exerted on the lawn mower?

Answer 1

The mass is 25kg and the normal force is 299N

Answer 2

The mass of the lawn mower can be calculated from the expression force is equal to the product of mass and acceleration. We do as follows:

F = ma
70 = m(1.8)
m = 38.89 kg

The normal force is the upward force perpendicular with the object. For this case it is equal with Wcos(50). We calculate as follows:

Fn = Wcos50 = 38.89(9.81)(cos50) = 245.23 N