<span>47 amu is the correct answer</span>
The minimum coefficient of static friction between the pavement and the tires is 0.69.
The given parameters;
- <em>radius of the curve, r = 90 m</em>
- <em>angle of inclination, θ = 10.8⁰</em>
- <em>speed of the car, v = 75 km/h = 20.83 m/s</em>
- <em>mass of the car, m = 1100 kg</em>
The normal force on the car is calculated as follows;

The frictional force between the car and the road is calculated as;

The net force on the car is calculated as follows;


Thus, the minimum coefficient of static friction between the pavement and the tires is 0.69.
Learn more here:brainly.com/question/15415163
Answer
given,
mass of the crate = 53 Kg
force applied by the worker = 180 N
Angle made with the horizontal = 35°
crate moves = 2.9 m
a) The work done equals the force in the direction of the displacement, times the displacement
W = F_x ×d
W = 180 cos 35° × 2.9
W = 427.6 J
b) A force that is perpendicular to the direction of the displacement does not do any work so work done by gravitational force is zero
c) Similarly for the normal force the work done will be zero.
d) Total work done by the crate is equal to 427.6 J
This is easy
Number 2 is 20 N to the right
Number 3 is 30 N up
Both are unbalanced