Question

A person pushes a 16.0 kg lawn mower at constant speed with a force of 87.5 N directed along the handle, which is at an angle of 45.0 to the horizontal. Part D friction force? What force must the person exert on the lawn mower to accelerate it from rest to 1.3 m/s in 2.5 seconds, assuming the same Express your answer to three significant figures and Include the appropriate units

Answer 1

Answer:

61.87 N

99.3 N

Explanation:

Part D)

Consider the forces acting on the lawnmower

F = Applied force = 87.5 N

θ = Angle of the applied force with the horizontal = 45

m = mass of the lawnmower = 16 kg

f = frictional force

a = acceleration along the horizontal direction

Force equation along the horizontal direction is given as

F cosθ - f = ma

(87.5) Cos45- f = (16) (0)

f = 61.87 N

Part E)

v₀ = initial velocity = 0 m/s

v = final velocity = 1.3 m/s

t = time interval = 2.5 sec

a = acceleration

using the equation

v = v₀ + at

1.3 = 0 + a (2.5)

a = 0.52 m/s²

Force equation along the horizontal direction is given as

F cosθ - f = ma

F Cos45- 61.87 = (16) (0.52)

F = 99.3 N