Final answer:
The friction force on the truck can be calculated using the formula friction force = coefficient of static friction × normal force. To find the coefficient of static friction, you need to know the applied force required to start the motion of the truck on the slope.
Step-by-step explanation:
The friction force on the truck can be determined using the formula:
Friction force = coefficient of static friction × normal force
Since the truck is parked on a slope, the normal force can be calculated as:
Normal force = mass × gravity × cos(θ)
Substituting the given values, the normal force is:
Normal force = 4000 kg × 9.8 m/s² × cos(15°)
Once you have the normal force, you can calculate the friction force using the given coefficient of static friction.
To find the coefficient of static friction, you need to know the applied force required to start the motion of the truck on the slope. This force is equal to the product of the static friction coefficient and the normal force.