Fg, Fn, Ft, Fnet

In the figure, what does the spring scale read? The pulleys are ideal and the strings and scale are also massless.

• exactly 2.0N
• exactly 1.0N
• 0.50N
• 0.00N

Two boxes P and Q on a perfectly smooth horizontal surface are connected by a light horizontal cord. The mass of P is greater than that of Q. A horizontal force is exerted on box Qas shown in the figure, accelerating the bodies to the right. The magnitude of the force exerted by the connecting cord on body P is

• zero
• less than F but not zero
• equal to F
• greater than F

Two boxes, A and B, are connected by a horizontal string S on a horizontal floor. A very light wire pulls horizontally on box B, as shown in the figure, exerting a force of 100 N. The Newton’s third law pair force to this pull is

• the pull that  box B exerts on string S.
• the pull that string S exerts on box B.
• the pull that string S exerts on box A
• the pull that box B exerts on the wire.

A car of mass 1100 kg that is traveling at 27 m/s starts to slow down and comes to a complete stop in 578 m. What is the magnitude of the average stopping force exerted on the car?

• 690N
• 550N
• 410N
• 340N

A box of mass 72 kg is at rest on a horizontal frictionless surface. A constant horizontal force of magnitude F then is exerted on the box, accelerating it to the right. You observe that it takes the box 3.4 seconds to travel 13 meters. What is the magnitude of the force F?

• 275N
• 160N

A 50.0-kg crate is being pulled along a horizontal smooth surface. The pulling force is 10.0N and is directed 20.0° above the horizontal. What is the magnitude of the acceleration of the crate?

• 0.0684 m/s²
• 0.188 m/s²
• 0.200 m/s²
• 0.376 m/s²

A piano mover raises a 1000-N piano at a constant speed using a very light rope in a frictionless pulley system, as shown in the figure. What is the force that the mover is exerting on the rope?

• 2000N
• 1000N
• 500N
• 250N

A 400-kg box is lifted vertically upward with constant velocity by means of two cables pulling at 40.0° on either side of the vertical direction. What is the tension force that each cable exerts on the box?

• 231N
• 400N
• 800N
• 2560N

A 10-kg sign is held by two ropes as shown in the figure. What is the tension force that rope A exerts on the sign?

• 44N
• 69N
• 72N
• 88N

If you normally weigh 706 N, what is your apparent weight if you are in an elevator that is slowing down at the rate of 1.65 m/s² ?

• 825N
• 587N