Chapter 4 - Science

1.

1 point

Lifting a 50 kg mass 2m overhead requires about how much work?

100 J

2500 J

1000 J

25 J

2.

1 point

Which of the following is not one of the 3 ways that machines can make work easier

changing the direction of the force

increasing the distance over which the force is applied

increasing the force you can apply to an object

decreasing the amount of energy required to do the work

3.

1 point

An example of a contact force could be

magnets sticking together

a hockey stick moving a puck

static electricity pulling two balloons together

gravity holding us to the earth’s surface

4.

1 point

The statement: “the total amount of energy in a system remains constant” is referred to as

The law of conservation of energy

quantum energy

The law of transformation of energy

The samey-samey-energy-thingy

5.

1 point

Mechanical Advantage is expressed in the following units:

Newtons (N)

Mass (kg)

Joules (j)

Mechanical Advantage has no units

6.

1 point

A machine is constructed to raise a box of potatoes to the top shelf. The box of potatoes is 3000 N and the machine will provide a mechanical advantage of 3. How much input force will be needed to lift the box?

6000 potatoes

9000 N

300 N

1000 N

7.

1 point

The following is true of energy

it changes for an object whenever work is done on it

it can transfer from one object to another, or change form

It is measured in units called joules (J)

all of the above

8.

1 point

For an object on earth weighing 450 N, what would it’s approximate mass be?

9.8 kg

45 kg

4500 kg

225 kg

9.

1 point

A machine is . . .

an system that decreases the amount of effort to reduce friction

any mechanism that has moving parts

any mechanical system that reduces the force required to do work

none of the above

10.

1 point

An object has a mass of 75 kg, and a weight of 735N on earth. What might it’s weight on the moon be?

122.5 kg

735 N

75 kg

122.5 N

11.

1 point

Mechanical Advantage can be defined as follows

The amount that a machine can multiply the force applied to an object

The force required to move an object without a machine divided by the input force with the machine

The force applied to a machine divided by the input force with the machine

all of the above

12.

1 point

The ratio of kilograms to Newtons is approximately...

1:1000

1:10

1:100

1:1

13.

1 point

Which of the following is not an example of potential energy

Magnetic

Motion

Chemical

These are all types of potential energy

14.

1 point

The mass of an object can be described in the following way:

The number of Kilograms measured for an object

The force of gravity exerted by an object

The number of Newtons measured for an object

None of the above

15.

1 point

A fixed pulley system is built by placing a pulley overhead with one end of a rope tied to the load, and the other end left to be pulled down by someone.
This fixed pulley would be expected to provide a mechanical advantage...

equal to one, because there should be no friction with only one pulley

equal to one half, meaning you can only lift half what you could without using the machine

a bit less than one, due to friction

equal to two, meaning it is twice as easy to lift the load

16.

1 point

Gravity could best be defined as...

the weight of an object

the attraction between two objects due to their mass

both a and b

neither a nor b

17.

1 point

ideal mechanical advantage differs from mechanical advantage because...

it is a ratio of the input and output distances

it has no friction

neither a nor b

both a and b

18.

1 point

Friction is . . .

the heat generated by an object

the sound energy from objects in contact

the force that opposes the reletive motion of an object

none of the above

19.

1 point

An example of a force which doesn’t require any contact could be...

static electricity sticking a balloon to the wall

neither a nor b

magnets interfering with a compass

both a and b

20.

1 point

An object has a mass of 75 kg, and a weight of 735N on earth. What might it’s mass on the moon be?

122.5 N

75 kg

122.5 kg

735 N

21.

1 point

Biff is competing with Chachi to see how long they can hold a 50 kg box of potatoes. A coworker sees them sweating and under obvious stress, but tells them that they are not actually doing work in the scientific sense. Is this true?

Yes, because they are not moving during the contest

No, because holding a box of potatoes has nothing to do with science

No, because the longer they hold it the more tired they will become

Yes, because all the force needed to lift the box has already been done

22.

1 point

When jacking up a car, Wei pushes with a force of 250 N on the handle of a jack and the jack applies a force of 3000 N to the car. What is the mechanical advantage of this car jack?

12

1

3250

0.083

23.

1 point

A man pulls his 4 children down the road on a toboggan in the middle of summer for no reason. The kids and the toboggan combine to weigh 2600N and he pulls it 20m before taking a break. How much work has he done?

130 J

52000 J

5200 J

13000 J

24.

1 point

Which of the following scenarios describes potential energy

a skateboard is being ridden down a long flat road

a stretched elastic band is seen wrapped around a bundle of mail

an elevator is travelling to the top of the CN Tower

A lightning bolt brightens the night sky

25.

1 point

Ideal Mechanical Advanatge can be calcualted using the following formula

IMA = Fin/Fout

IMA = Fout/Fin

IMA = dout/din

IMA = din/dout

26.

1 point

Which of the following is not an example of kinetic energy

Thermal

Sound

Light

These are all types of kinetic energy

27.

1 point

A force that can transfer without contact is also called

“quantum-entanglement”

“ force-of-nature”

“action-at-a-distance”

“motion-from-afar”

28.

1 point

In science, work is . . .

the effort required to maintain an object at rest

the effort used apply a force to make objects move over a distance

the amount of friction required to slow down a moving object

none of the above

29.

1 point

Work can be calculated with the following formula:

W = Fd

W = mg

W = m/s2

W = Fin/Fout

30.

1 point

Which of the following does not affect the pull of gravity

the volume of the object

the distance between objects

the mass of an object

none of the above

31.

1 point

The force of gravity can be found with the following formula:

g = 9.8 m/s^2

F = mg

Fin = Fout/MA

F = Wd

32.

1 point

The following are examples of effects that friction may have on an object

the object gains thermal energy

the object makes noise

the object slows down

all of the above

33.

1 point

A student has forgotten his locker combination after a long weekend and Mr. Moscatel has no choice but to cut it off. He uses a bolt cutter because...

He can apply a small force over a longer distance by using the handles

He can apply a great force over a small distance where the cutter meets the lock

both a and b are correct

neither a nor b are correct

34.

1 point

A force can be defined as

a push that acts on an object

a pull that acts on an object

either a or b

neither a nor b

35.

1 point

The following facts are true with respect to mass

1000g = 1L of water

1 g = 1000 kg

9.8kg = 1N

all of the above