A clothesline is stretched taut between two poles. Then a wet towel is hung at the center of the line. Can the line remain horizontal? Explain.

The net force on a moving object is suddenly reduced to zero and remains zero. As a consequence, the object $(a)$ stops abruptly, $(b)$ stops during a short time interval, (c) changes direction, (d) continues at constant velocity, (e) changes velocity in an unknown manner.

A sky diver of weight $w$ is descending near the surface of the earth. What is the magnitude of the force exerted by her body on the earth? (a) $w$. (b) Greater than $w$. (c) Less than w. $(d) 9.8 w .(e) 0 .(f)$ It depends on the air resistance.

In which of Erikson's stages does a child learn self-control and begin to feel more capable? a. autonomy versus shame and doubt b. initiative versus guilt c. industry versus inferiority d. identity versus role confusion

Suppose you observe an object from a reference frame and find that it has an acceleration $\vec{a}$ when there are no forces acting on it. How can you use this information to find an inertial frame?

For an observer in an inertial reference frame, identify which (if any) of the following statements are true and which (if any) are false. (a) If there are no forces acting on an object, it will not accelerate. (b) If an object is not accelerating, there must be no forces acting on it. (c) The motion of an object is always in the direction of the resultant force. (d) The mass of an object depends on its location.

Which of the free-body diagrams in Figure 4-34 represents a block sliding down a frictionless inclined surface?

Consider any situation in which an external force, say a push, is applied to an object. If Newton's third law requires that for every action there is an equal and opposite reaction, why doesn't the reaction force always cancel out the applied force, leaving no acceleration at all?

Emily holds a banana of mass $m$ over the edge of a bridge of height $h$. She drops the banana and it falls to the river below. Use conservation of energy to show that the speed of the banana just before hitting the water is $v=\sqrt{2 g h}$.

What will be the kinetic energy of a pile driver ram when it undergoes a 10-kJ decrease in potential energy?

A baseball player hits a ball with a bat. If the force with which the bat hits the ball is considered the action force, what is the reaction force? (a) The force the bat exerts on the batter's hands. (b) The force on the ball exerted by the glove of the person who catches it. (c) The force the ball exerts on the bat. (d) The force the pitcher exerts on the ball while throwing it. (e) Friction, as the ball rolls to a stop.

A slowly moving ship can have a greater momentum than a fast-moving racing car when _______.

What impulse occurs when an average force of 10 N is exerted on a cart for 2.5 s?

What is the momentum of an 8-kg bowling ball rolling at 2 m/s?