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Physics Midterm review

A Net force on an object of 10 kg is 10 N. What is the acceleration of the object?

1 m/s/s

Terminal speed occurs when:

force of gravity (weight) = air resistance up

If you exert the same force on Earth that Earth exerts on you, why doesn’t Earth move up to meet you when you jump off its surface?

it has too much mass

Gwen rides her bicycle 2.4 kilometers up a steep hill in 8 minutes. Her speed is ____ kilometers per minute.

0.3 km/min

The slope of a distance time graph is the ____________.

average speed

A word meaning “size”often used to describe scalar quantities is:

magnitude

What is the weight in newtons of a 15-kilogram toddler on Earth?

150 N

The weight of a 10 Newton object is .....

10 Newtons

Maya kicks a soccer ball with 4 newtons North. At the exact same time, Casey kicks the same ball 8 N West. The resultant force of the soccer ball is about _____ Newtons.

8.9 N NW

The diagram below represents a box sliding down an incline: The force of friction acting on the box is directed toward:

2

An unbalanced force of 30 N gives an object an acceleration of 6.0 m/s2. What force would be needed to give it an acceleration of 1.0 m/s2?

5 N

The inertia of two objects must be the same if the same force causes the same ____?

acceleration

If you know the distance traveled and the amount of time it took, speed may be calculated by:

dividing distance by time

If the net force acting on a moving object is zero, the object will do what in regards to speed and direction?

continue in the same direction with no change of speed.

Name THREE physics scientists...

Aristotle, Einstein, Newton, Joule, Watt, Hooke, Bohr, Rutherford, Millikin,

If I lift up a brick, I am lifting up the _______ of the object.

weight

A rocket can fly into space because what pushes on the rocket?

The exhaust gases

Two forces are applied to a 2.0-kilogram block on a frictionless, horizontal surface, as shown in the following diagram. What is the acceleration (speed and direction).

3 m/s/s right

If there are two forces on an object, 20 N and 30 N, what are the MINIMUM and MAXIMUM resultants possible?

10 N and 50 N

Shawna, who weighs 54 kilograms, is roller blading on a level surface. If she is rolling at 12 meters per second, to what height would she roll up an incline before stopping? (Assume there is no friction.)

7.3 meters

The rate of change in the speed of an object is known as:

acceleration

Physics is the study of matter and __________

energy

A 2.2-kilogram crate is pulled by a 30-newton force over a distance of 5 meters. The work done by pulling the crate is ____ joules.

150 Joules

if a am moving at 50 m/s and a force stops me in 5 seconds, my acceleration is (be careful sign matters and unit matters)

-10 m/s/s

For every action there is a (n) ________ and opposite reaction, and is the basis for what law?

equal / Newton's third law

What is the unit of Work called?

Joule

F = ma relates to what law?

Newton's Second law

Two forces act on you when you are standing motionless on the floor, the force due to gravity and the force of the floor. These two forces are equal and opposite. Are they the action- reaction forces?

NO!

The weight of a 10 kg object is....

100 Newtons

The metric unit of force preferred by scientists is the:

Newton

Lifting a 70-kilogram barbell 2.0 meters above the floor increases its potential energy by about:

1400 Joules

An object at constant speed means the sum of the forces =

Zero

The motion of an object will continue in the same direction at the same speed unless the object is acted upon by a(n) ____________________.

unbalanced force

When you are seated in a chair, the force exerted by you on the chair is called the:

weight

According to Figure 2-1A, what is the speed of the 2.0-kilogram mass when the time equals 5 seconds?

3 m/s

Put these in order from lowest to highest.
1 Megameter, 1 cm, 1 mm, 1 meter, 1 nanometer, 1 Gigameter

nm, mm, cm, m, Mm, Gm

On the surface of Jupiter, the acceleration due to gravity is about 3 times that on Earth (g=29.4 m/s/s). How much would a 0.40-kg rock weigh on Jupiter?

11.76 N

“Energy can never be created or destroyed, just transformed from one form to another” is a statement of the law of ______________________________ (three words).

Law of conservation of energy

Which is bigger, a 100 centimeters or 1000 millimeters?

They are the same

Emma walks to school at a speed of 3 miles per hour. If it takes her 20 minutes to walk from home to school, how many miles away is the school from her house?

1 mile

A 20-kg block of cement is pulled upward (not sideways!) with a force of 400 N. What is the acceleration of the block?

10 m/s/s

The rate of doing work is called ....

POwer

The slope of a distance time graph is the object's....

average velocity

Which has more Inertia 10 kg object or a 50 kg object?

50

The kinetic energy of an object depends upon two things: ____________________ and ____________________.

mass and velocity

How fast is a freely falling object going when it falls for 9 seconds?

90 m/s

Energy that is stored due to the position of an object may be called ____ energy.

Potential

The unit Joule / second is the same as .....

Watt

A ball is being twirled on the end of a string as pictured in the diagram: If the string is released when the ball reaches point P, the inertia of the ball will cause it to move in the direction of:

C

When you are seated in a chair, the force exerted on you by the chair is called the:

Normal force

Calculate the number of millimeters in 2.13 kilometers.

2130000

The measure of how effective a machine is in using energy to do work is called its _________

efficiency

The pulling force that always acts along the direction of the rope in a pulley system is called ____________________.

Tension

The slope of a speed versus time graph represents the...

acceleration

The expression mgh represents _________________________ energy.

Potential

The graph below represents the motion of a moving vehicle. What is the speed of the vehicle during the time interval from t = 2.0 seconds to t = 4.0 seconds?

10 m/s

If there are two forces on an object, one of 10 N and the other of 20 N, could 28 N be the resultant?

yes

In space, does an object have mass?

YES

He believed that all objects keep moving because you stopped pushing them.

Aristotle

How many seconds in one week?

604800

A measured quantity that is described by stating a size and a direction is called a:

Vector

Convert 200 cm to meters

2 meters

Physics is ________.

Phun

Doug rides a motorcycle at an average speed of 42 miles per hour for 3.6 hours. The distance he travels is about ____ miles.

151 miles

What law: I hit a wall and feel the wall hitting me

Newton's Third law

When you drop a sheet of crumpled paper and a sheet of flat paper off a table at the same time, why does the flat sheet of paper hit the ground later?

air friction

What is the speed of a 5 kg object falling to the bottom of a 5 meter tall hill?

10 m/s

The Newton is defined as the force of that can give a ______kg object an acceleration of ________ m/s/s,

1

What concept: Two forces cancelling each other out, so they exist, but they add up to zero.

Vector addition or equilibrium

Newton's First Law is sometimes called the law of what?

Inertia

The acceleration due to gravity is:

9.8 m/s/s

Work may be measured using units of:

Joules

A Net force on an object of 10 kg is 10 N. What is the acceleration of the object?

1 m/s/s

A 30-kg girl runs up the staircase to a floor 5 m high in 8 seconds. What is her power output?

187.5 Watts

The metric unit of mass, distance and time preferred by scientists are the:

kilogram, meter, second

A 60-kg person on in-line skates pushes against a wall with a force of 30 N and recoils. What acceleration does that person experience?

0.5 m/s/s

A speeding truck makes contact with a bug on its windshield. Compare the force that the bug exerts on the truck to the force the truck exerts on the bug.

Forces are the same for both

An object falls without friction near Earth’s surface. The loss of its potential energy is equal to its gain in ___________ energy

Kinetic

Calculate the power required to move a 2,000-kilogram automobile to the top of a 100-meter hill in 15.0 seconds. Express the power both in units of watts and horsepower.

133333.33 Watts

What is the name of a rock flying through space BEFORE it enters the atmosphere?

Meteor or Asteroid

According to Figure 2-1A, during which interval is the object accelerating at the greatest rate?

A to B

How far does a freely falling object fall for 12 seconds?

720 meters.

Convert 150 cm to meters

1.5 meters

What is the reaction force to your weight?

You pull the Earth

Speed with a direction is called ______________________.

velocity

The following forces act on an object: 9 N north, 52 N south, and 55 N west. What is the magnitude of the net force? (direction also)

69.8 N SW

A skydiver reaches an instantaneous velocity of 88.2 meters per second before opening his parachute. How long was he in free fall?

9 seconds

The unit Newton*meter is the same as a ...

Joule

What law: It's HARDER to push a BIG rock than a pebble from rest due to this.

First law

An object in motion wants to stay in motion, and an object at rest wants to stay at rest, is a way of stating _______________________________.

Newton's first law

An object accelerating toward Earth under only the influence of the force of gravity is said to be in ____________________ (two words).

free fall