Physics Ch.4

Whenever the net force on an object is zero, its acceleration

• may be less than zero

• zero

• may be more than zero

If you double the net force on an object, you'll double its

• acceleration

• speed

• velocity

• all of the above

A 300-kg bear grasping a vertical tree slides down at constant velocity. The friction force between the tree and the bear is

• 30 N

• 300 N

• 3000 N

• More than 3000 N

A 1-kg mass at the Earth's surface weighs

• 1 N

• 5 N

• 10 N

• 12 N

Compared to a 1-kg block of solid iron, a 2-kg block of solid iron has twice as much

• inertia

• mass

• volume

• all of the above

Strange as it may seem, it is just as difficult to accelerate a car on a level surface on the Moon as it is here on Earth because

• the mass of the car is independent on gravity

• the weight of the car is independent of gravity

• both of these

• neither of these

At equilibrium on a bathroom weighting scale, the downward pull of gravity on you is balanced by

• your weight

• an upward support force

• your mass

A heavy ball hangs by a string, with a second string attached to its bottom. A quick pull on the bottom string breaks the

• top string

• bottom string

• top or bottom string equally

When the bottom string is pulled slowly in the heavy-ball-and-strings demonstration, tension

• in the top string is due to your pull plus the weight of the ball

• is about the same in both strings

• in the bottom string zero

If the mass of a cart is quickly loaded to have twice the mass while a propelling force remains constant, the cart's acceleration

• quadruples

• doubles

• stays the same

• halves