Two workers are sliding 450 kg kg crate across the floor. One worker pushes forward

The coefficient of kinetic friction on the floor is 0.138

Explanation:

Given;

mass of the crate, m = 450 kg

force applied by the first worker, F₁ = 380 N

force applied by the second worker in the same direction as the first worker, F₁ = 230 N

frictional force opposing the motion of the box = -

Apply Newton's second law of motion;

∑F = ma

If the crate slides with constant speed, acceleration is zero (0).

Therefore, the coefficient of kinetic friction on the floor is 0.138

The value of bending stress on the pinion 35.38 M pa

Explanation:

Given data

m = 2 mm

Pressure angle = 20°

No. of teeth T = 17

Face width (b) = 20 mm

Speed N = 1650 rpm

Power = 1200 W

Diameter of the pinion gear

D = m T

D = 2 × 17

D = 34 mm

Velocity of the pinion gear

Form factor for the pinion gear is

Y = 0.303

Now

Force on gear tooth

F = 408.73 N

Now the bending stress is given by the formula

= 35.38 M pa

This is the value of bending stress on the pinion