Block A in the figure has a mass of 4.5 kg, and block B has a mass of 12.0 kg. The coefficient of kinetic friction between block B and the horizontal surface is 0.35. a) What is the mass of block C if B moves to the right with an acceleration of 2.5 m / s^2? b) What tension is there in each string in such a situation?

A block of mass M is suspended at rest by two strings attached to walls, as shown in the figure. The left string is horizontal with tension force T2 and and the right string with tension force T, makes an angle e with the horizontal. g is the magnitude of the gravitational acceleration. Which of the following statements is true? Select all apply. T2 M O The net force along the y-component is non-zero. O The acceleration along the x-component is zero. O The net force along the x-component is zero. O The acceleration along the y-component is non-zero. O The acceleration along the y-component is zero. O The acceleration along the x-component is non-zero. O The net force along the y-component is zero. O The net force along the x-component is non-zero.

A100-kg sofa needs to be moved across a level floor. The coefficient of static friction between the sofa and the floor is 0.40. Two physics students decide to apply a force F!" on the sofa. One student recommends that the force be applied upward at an angle theta above the horizontal. The other student recommends that the force be applied downward at an angle theta below the horizontal. Explain which student has the better idea and why.

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 8 kg decoration hangs from the ceiling. It is suspended by 2 wires. The first wire forms a 40⁰ angle with the ceiling. The second wire forms a 50⁰ angle with the ceiling.a. Find the tension in the 2 wires (including magnitude and direction) b. Assuming the wire that forms the 40⁰ angle with the ceiling has a length of 0.3 metres, how farbelow the ceiling is the decoration suspended?

A cardboard box rests on the floor of an elevator. The box has a mass m = 2.75 kg and the elevator has an upward acceleration of a.   a.  Write an expression for the sum of the forces acting on the box in the y-direction, ΣFy, given that up is the positive y-direction. Your answer should be in terms of FN, m, and g.  b. Write an expression for the normal force, FN, that the block experiences in terms of the elevator's acceleration, the block's mass, and the acceleration of gravity.  c.  If the elevator's acceleration has a magnitude of g in the downward direction, what would the normal force, FN1 be in Newtons?  d.If the elevator's acceleration had a magnitude of g in the upward direction, what would the normal force FN2 be in Newtons?

A box of mass ?=24.5 kg is pulled up a ramp that is inclined at an angle ?=19.0∘ angle with respect to the horizontal. The coefficient of kinetic friction between the box and the ramp is ?k=0.345 , and the rope pulling the box is parallel to the ramp. If the box accelerates up the ramp at a rate of ?=2.09 m/s2, calculate the tension ?T in the rope. Use ?=9.81 m/s2 for the acceleration due to gravity.

A 4 kg block is sliding down a vertical wall while being pushed by an external force as shown in the figure. What is the magnitude of the acceleration of the block (in m/s2) if the coefficient of kinetic friction between the wall and the block is uj, = 0.20 and the magnitude of the external force is 20 N? 4 kg 30 X 8.8