Module 01 Physics

A 10-N falling object encounters 10 N of air resistance. The net force on it is

0 N

A mosquito flying at 3 m/s encounters a 3-m/s breeze blowing in the opposite direction, which gives it a resulting speed over the ground of

0 m/s

The gain in speed each second for a freely falling object is about

10 m/s

Any falling object that gains a velocity of 10 m/s each second has an acceleration of

10 m/s^2

Ten seconds after starting from rest, a freely-falling baseball will have a speed of about

100 m/s

A 10-kg mass at Earth's surface weighs about

100N

The support force on a 10-N book that rests on a horizontal surface is

10N

Daisy weighs 120 N and carries Trixie who weighs 40 N on her back. The support force on Daisy's feet is

160 N

When Jean hikes a distance of 1 km in a time of one-half hour her average speed is

2 km/h

A 50-N object falling in air experiences 30 N of air resistance. The amount of net force on the falling object is

20 N

The average speed of a horse that gallops a distance of 10 km in a time of 30 min is

20 km/h

You're driving in a car at 50 km/h and bump into a car ahead traveling at 48 km/h in the same direction. The speed of impact is

2km/h

A 3000-N bear grasping a vertical tree slides down at constant velocity. The friction force between the tree and the bear is

3000 N

If you toss a ball straight upward at 40 m/s, with no air resistance it returns to you at a speed of

40 m/s

Burl and Paul have a total weight of 1300 N. The tensions in the ropes that support the scaffold they stand on add to 1700 N. The weight of the scaffold itself must be

400 N

An object is pulled with two forces, 10 N northward and 15 N southward. The magnitude of the net force is

5 N

When a 10-kg block is simultaneously pushed toward the east with 20 N and toward the west with 15 N, the combination of these forces on the block is

5 N east

Nellie runs the length of a 100-yard football field in a time of 20 seconds. Her average running speed is

5 yds/s

A girl pushes a cart to the left with a 100-N force. At the same time a boy pushes it to the right with a 50-N force. The net force exerted on the cart is

50 N on the left

A mosquito flying at 3 m/s encounters a 3-m/s breeze blowing in the same direction, which gives it a resulting speed over the ground of

6 m/s

Six seconds after starting from rest, a freely-falling baseball has a speed of

60 m/s

An object in free fall has a speed of 60 m/s. One second later its speed is

70 m/s

The scientist first credited for discovering the concept of inertia was

Galileo

When you stand at rest on a pair of bathroom scales, the readings on the scales will always

add to equal your weight

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

all of the above

The equilibrium rule states that the vector sum of all forces acting on a

all of the above

The resistive force of friction occurs for

all of the above

Which has zero acceleration?

all of the above

The net force on an object is

all the forces acting on it at once

Which has the greatest mass?

automobile battery

Given that two forces of 10 N and 15 N act horizontally (one dimension) on an object, the net force must

be either 5 N or 25 N.

If Burl carried Paul piggy-back while standing in the middle of a scaffold, the tensions in the two supporting ropes would

be equal

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

bottom string.

As you jump up and down on a floor, the support force by the floor experiences

changes

The two measurements necessary for calculating average speed are

distance and time

Aristotle treated motion by

dividing it into two classes.

A bucket of cement is raised by a rope at constant speed at a construction site. Compared with the force of gravity on the bucket, the upward force supplied by the rope is

equal

Marie pushes horizontally on her desk, but not hard enough to get it moving. The friction force acting on the desk is

equal and opposite to her push

Burl and Paul on a sign-painting scaffold are in equilibrium, which means that the net upward supporting force of the vertical ropes is

equal and opposite to the combined weights of Burl, Paul, and the scaffold.

According to Galileo, the test of scientific truth is

experiment

Science greatly advanced when Galileo favored

experiment

In contrast to Aristotle's way of explaining nature, Galileo relied on

experimental

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

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

Joshua stands on a floor that supports him. When Sydney rides piggy-back on Joshua, the support force by the floor beneath Joshua

increases

A glance at the speedometer on your vehicle will tell you your

instantaneous speed

When a ball increases in speed by the same amount each second, its acceleration

is constant

Once a basketball player's feet are off the floor in making a jump, the jumper's acceleration

is g; no more, no less.

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

is zero

According to Aristotle, a rolled ball eventually comes to a stop because

it seeks its natural state of rest

Galileo said that if you rolled a ball along a level surface it would

keep rolling without slowing down if no friction acted upon it.

A chunk of gold weighs 1 N on Earth. On the Moon its weight would be

less

On the surface of the Moon where acceleration due to gravity is less, a person's hang time would be

longer

A kilogram is a measure of an object's

mass

A kilogram is a unit of

mass

Between mass and weight, the more fundamental quantity is

mass

Shake an object to and from if you want to judge its

mass

An object is pulled with three forces: one at 20 N to the right, another at 40 N to the right, and the third at 30 N to the left. The net force is

none of the above

Compared with a 1-kg block of solid iron, a 2-kg block of solid iron has the same

none of the above

According to Galileo, inertia is a

property of all matter

An object is pulled with two forces, 10 N northward and 15 N southward. The direction of the net force is to the

south

When Marie pushes her desk to the right, friction between the floor and the desk acts toward

the left

A chunk of metal has a mass of 1 kg on Earth. If the same chunk were on the Moon its mass would be

the same

As an object freely falls, its

velocity increases

Acceleration and velocity are

very different from each other

The quantity that most relates to the size of an object is

volume

Lift an object against the force of gravity if you want to judge its

weight