Physics : chapter 6

When an object reaches terminal velocity its acceleration is

0 m/s

If a truck has ten times the mass of a car and the two vehicles are pushed with an equal force, you would expect the acceleration of the truck to be

1/10 times that of the car.

If shopping cart A has five times more mass in it than shopping cart B and the two carts are pushed with equal forces, you can expect the acceleration of shopping cart A to be

1/5 times that of shopping cart B

10-kg brick and a 1-kg book are dropped in a vacuum. The force of gravity on the 10-kg brick is

10 times as much as the force on the 1-kg book.

A box is dragged at a constant velocity in a straight-line path across a level surface by a force of 13 N. What is the frictional force between the box and the surface?

13 N

20-N falling object encounters 4 N of air resistance. The magnitude of the net force on the object is

16 N

Suppose the force of friction on a sliding object is 25 N. The force needed to maintain a constant velocity is

25 N

The acceleration produced by a net force on an object is

a. directly proportional to the magnitude of the net force. b. in the same direction as the net force. c. inversely proportional to the mass of the object.

You are on a frozen pond, and the ice starts to crack. If you lie down on the ice and begin to crawl, this will

decrease the pressure on the ice.

Distinguish between force and pressure.

force is a push or a pull. pressure is a force per unit area.

Pressure is defined as

force per area.

Accelerations are produced by

forces

How does acceleration of an object change in relation to its mass?

inversely proportional.

If the force acting on a cart doubles, what happens to the cart's acceleration?

it halves

Suppose a cart is being moved by a force. If suddenly a load is dumped into the cart so that the cart's mass doubles, what happens to the cart's acceleration?

it halves

unit of pressure is

newtons per square meter

What is terminal speed? When a skydiver has reached terminal speed, what is the air resistance equal to? What is the skydiver's acceleration?

terminal speed is when the force of air resistance is equal to the sky diver's weight. There are no longer any net forces acting on the sky diver and he stops accelerating.

The reason a tennis ball and a solid steel ball will accelerate at the same rate, in the absence of air resistance, is that

the ball with the larger force also has the larger mass.