A 4.0 kg crate is pulled across a level floor and moves at a steady 1.2 m/s. The rope pulls 18 N forward. Which statement follows from the motion alone?

Two students on skateboards, 40 kg and 60 kg, push off from each other. One says, "The 60 kg student pushes harder, so the 40 kg student moves faster." Which correction is right?

Use the free-body diagram. Taking right as positive, what is the 2.0 kg box's acceleration?

A cart compresses a spring with spring constant k = 200 N/m by 0.15 m. What is the magnitude of the spring's restoring force?

Which base-unit combination is equivalent to 1 newton?

A ball moves at constant speed in a horizontal circle. Which statement must be true?

A student says, "A 5 kg rock falls faster than a 1 kg rock because it has more weight." Ignoring air resistance, which correction is right?

A 5.0 kg crate is pushed right with 30 N on a level floor. The coefficient of kinetic friction is 0.20. What is the crate's acceleration?

The diagram shows a crate with zero vertical acceleration. What magnitude belongs on the unlabeled normal-force arrow?

In a forces lab, which quantity should be reported in kilograms rather than newtons?

An elevator is moving upward at a constant 2.0 m/s. Which statement follows before any calculation?

A sliding puck on a rough floor slows after a push. A student says, "It slows because the forward force runs out." Which correction is right?

A 4.0 kg mass hangs from a rope and accelerates upward at 1.5 m/s². What is the rope tension?

In the diagram, which two forces are an action-reaction pair?

A data table lists μs = 0.60 for rubber on dry concrete. What unit should be written with μs?

A book is at rest on a rough incline and would slide down if the surface were smooth. Which force direction follows from the motion?

A book rests on a table. A student says, "The table's push on the book and the book's push on the table cancel." Which correction is right?

A 0.25 kg ball on a 1.2 m string moves in a horizontal circle at 6.0 m/s. What tension supplies the centripetal force?

Use the free-body diagram. What is the 10 kg mass's acceleration?

A force-versus-extension graph for a spring has slope 120 N/m. What quantity is that slope?

A puck glides on nearly frictionless ice after a brief shove, and the shove is no longer acting. Which statement follows?

A student says, "A spinning yo-yo stays in a circle because a centrifugal force pulls it outward." Which correction is right?

A 12 kg box rests on a frictionless ramp tilted 25° above horizontal. What is the normal force on the box?

The diagram shows a sled moving at constant velocity. What magnitude belongs on the unlabeled friction arrow?

Which quantity describes an object's resistance to changes in its motion?

A car rounds a flat curve at constant speed. Which force on the car points toward the center of the curve?

A student says, "Mass and weight are the same because both tell how heavy something is." Which correction is right?

An 18 kg crate is pulled horizontally with 55 N, but it does not move. If μs = 0.40, what is the static friction force?

For the block on the incline, the downhill component of weight is 30 N. What is the net force along the slope?

A spring scale reads 68 N for a hanging object. Which quantity is the scale reporting?

A ball is thrown straight upward. At the highest point, ignore air resistance. Which force statement is correct?

A student says, "The normal force on an object always equals its weight." Which correction is right?

A 15 kg sled is pulled right with 70 N while kinetic friction is 25 N left. What is the sled's acceleration?

Use the free-body diagram. Taking right as positive, what net horizontal force is shown?

In a force-table lab, the symbol ΣF labels which quantity?

A crate is moving left but slowing down. Taking right as positive, what follows from the motion?

A student says, "A spring stretched twice as far pulls back with the same force because k is constant." Which correction is right?

What is the weight of a 65 kg person on Earth, using g = 9.8 m/s²?

Use the free-body diagram. What is the 5.0 kg box's acceleration?

The unit m/s² appears in a forces lab report. Which quantity does it label?

A sign hangs at rest from two vertical ropes. Which statement follows from the motion alone?

A driver says, "The engine pushes the car forward by pushing on the car." Which correction explains the external force that accelerates the car?

The diagram shows a 3.0 kg mass at rest. What magnitude and direction belong on the unlabeled tension arrow?

An 8.0 kg block is pulled across a level floor at constant speed by a 24 N horizontal force. What is the coefficient of kinetic friction?

A flat curve has radius 20 m and tire-road static friction coefficient 0.50. What is the greatest speed for a car before slipping?

A 50 kg rider stands on a scale in an elevator accelerating upward at 2.0 m/s². What does the scale read?

In tug-of-war, a student says, "The winning team pulls harder on the losing team." Which correction is right?

A 200 N sign is supported equally by two vertical ropes. What is the tension in each rope?

The left arrow points toward the center of the circle. For a 0.50 kg ball, what acceleration does the diagram imply?

A bus stops suddenly, and a passenger lurches forward. A student says, "A forward force throws the passenger." Which correction is right?