QUESTION 9 A box of mass 60 kg is pushed along flat ground by a force with a magnitude of 500 N. If the coefficient of kinetic friction between the box and the ground is 0.4, what's the magnitude of net acceleration of the box in the x-direction?

Consider an object at rest on a rough horizontal surface. Which of the following is necessarily correct if we use the model of friction described in the videos and book? The force of friction on the object is smaller than or equal to μg FN, where μs is the coefficient of static friction and FN is the normal force exerted on the object by the surface. The force of friction on the object is proportional to the normal force exerted by the surface on the object. The force of friction on any object opposes motion; since the object is at rest, the force of friction is zero. The force of friction on the object is proportional to the object's weight, i.e. Ff = p.mg, where μs is the coefficient of static friction, m is the mass of the object, and g is acceleration due to Earth's gravity.

A 235 N crate rests on a ramp; the maximum angle just before it slips is 27.8° with the horizontal. What is the coefficient of static friction between crate and ramp surfaces? Answer:

A 423 N crate rests on a ramp; the maximum angle just before it slips is 26.4° with the horizontal. What is the coefficient of static friction between crate and ramp surfaces?

6. A mass m1 = 4.90 kg block on a tabletop is attached by a string to a hanging block of mass m2 the figure. The coefficient of kinetic friction between the mass (m;) and the surface is 0.20. The blocks are released from rest and allowed to move freely. Find the magnitude of the tension in the string. 50 ssf60 ssf60 s 60 ssf60 ssfó0 ssf60 ssf60 ssf60 s 00 ssf60 2.30 kg, as shown in 60 sf60 ssf602 60 ssf60 ssf60sf60 60 ss sT60 ssf60 ssf60 ssf60 s ssf60 ssf60 ssf60 ssf60 ssf60 s 60 ssf60 ssf60

The figure shows three crates being pushed over a concrete floor by a horizontal force F of magnitude 695 N. The masses of the crates are m₁ = 31.5 kg, m₂ = 13.9 kg, and m3 = 20.2 kg. The coefficient of kinetic friction between the floor and each of the crates is 0.700. What is the magnitude F32 of the force on crate 3 from crate 2? m1 mq mg

In a movie, a stuntman places himself on the vertical front of a truck as the truck accelerates. The coefficient of static friction between the stuntman and the truck is 0.370. The stuntman is not standing on anything but can “stick” to the front of the truck as long as the truck continues to accelerate. What minimum forward acceleration will keep the stuntman on the front of the truck?

The 118-lb force P is applied to the 250-lb crate, which is stationary before the force is applied. Determine the magnitude and direction of the friction force F exerted by the horizontal surface on the crate. The friction force is positive if to the right, negative if to the left. Assume ??= 0.48, ??= 0.38.

A large cube (mass = M) being accelerated across a horizontal frictionless surface by a horizontal force . A small cube (mass = m) is in contact with the front surface of the large cube and will slide downward unless is sufficiently large. The coefficient of static friction between the cubes is u. What is the smallest magnitude that F can have in order to keep the small cube from sliding downward?