Physics final

My sister is traveling at a speed of 40 m/s when she sees the red light. She comes to a stop in 6.6 sec. What was her acceleration?

-6.1 m/s/s

Two freight trains of equal mass roll toward each other with the same speed. What is the combined momentum of the two trains?

0 kg m/s

A 100 kg mass has a density of 400 kg/m3. Its volume is

0.25 m ^3

A 1 kg chunk of putty moving at 1 m/s collides and sticks to a 5 kg bowling ball initially at rest. The bowling ball and putty then move with a momentum of

1 kg m/s

A 40% efficient machine is required to do 400 Joules of work during a cycle. How much energy does it consume during each cycle?

1000 Joules

After I push my 1800 N sister out of the airplane, she experiences 700 N of air resistance as she falls. What is the net force on my sister?

1100 N

The 6 kg bowling ball is initially at rest 2 meters above its lowest point. What is the potential energy of the ball at its highest point?

120 J

The 6 kg bowling ball is initially at rest 2 meters above its lowest point. what is the kinetic energy of the ball at the bottom of its arc?

120 J

I launch a water balloon at my sister from the top of a 45 m building with a horizontal speed of 40 m/s. How far from the building does the balloon land?

120 m

Some old physics prof pulls a cart across the room a distance of 5 meters. Afterward the cart has 70 Joules of kinetic energy. What force did he exert during the pull?

14 Newtons

A 3 kg ball has a momentum of 48 kg m/s. What is the ball's speed?

16 m/s

My sister weighs 1800 Newtons. What is her mass?

180 kg

Buoyant force is greatest on a submerged

2 kg mass of wood

An object has a speed of 4 m/s in the 1st second, 6 m/s in the 2nd second, 8 m/s in the 3rd second. The acceleration of this object is____

2 m/s/s

It would be harder to drink your Diet Dew through a straw if you were

20 km above ocean surface

A satellite in orbit at a distance of one earth radius has an apparent weight in that orbit of 500 N. When it lands on the earth, the force of gravity on the satellite is

2000 N

If you add 350 Joules worth of gasoline to your car and get only 87.5 joules of kinetic energy out of it. What is its efficiency?

25%

A 70 kg bungee jumper jumps from a height of 40 m. How much potential energy does she have just before jumping?

28, 000 J

Given that there are 2.54 cm in one inch, how many inches are in 75 meters?

2953

If a bridge is 50 m high, how long will it take my sister to hit the water below if I drop her from the bridge?

3.2 sec

The number, .0032, is written in scientific notation as,

3.2x10-3

3 seconds after starting from rest, a freely falling object will have a speed of,

30 m/s

I throw my sister upwards with a speed of 20 m/s. She comes back down and hits the ground in what total time?

4 seconds

My truck has a mass of 1000 kg. If I push on it with a net force of 4500 N, what will be the acceleration of my truck?

4.5 m/s/s

An asteroid exerts a 360 N force on a nearby spacecraft. If the spacecraft moves to a point 3 times as far from the center of the asteroid, the force will be

40 N

A 30 kg boy sits at a distance of 2 m from the center of a see-saw. What mass is his sister if she sits at the 1.5 meter mark to balance him?

40 kg

I drop my sister into a well and she hits bottom in 3 seconds. How deep is the well?

45 m

How much time would it take a 60 Watt light bulb to consume 300 Joules of energy?

5 seconds

A 5 kg fish swimming at a velocity of 1 m/s swallows an unsuspecting 1kg fish initially at rest. The speed of the larger fish after his lunch is

5/6 m/s

The 6 kg bowling ball is initially at rest 2 meters above its lowest point. How fast is the ball moving at the bottom of its arc?

6.3 m/s

The 6 kg bowling ball is initially at rest 2 meters above its lowest point. What is the kinetic energy halfway down?

60 J

If you are travelling at a speed of 30 m/s, what is your speed in miles/hour? There are 1609 meters in a mile.

67.1

The number, 6.96x104, could also be written as

69,600

What is your average speed if you travel 250 miles in 3.5 hrs?

71.4 mi/hr

Traveling at 10 mi/hr in a school zone requires 20 feet to stop your car. If you are traveling at 20 mi/hr, what distance would you need to stop?

80 feet

The 18/9 F isotope has

9 neutrons and 9 protons

My sister at a height of 25 m has a potential energy of 22,500 Joules. What is her mass?

90 kg

An object that has gravitational potential energy must be

At an elevated position

Scientific theories _______.

Explain why nature behaves the way it does

The 6 kg bowling ball is initially at rest 2 meters above its lowest point. Which is greater, the potential energy at 1m or the kinetic energy at 2m?

PE at 1m

The cardboard ice cream box in the freezer doesn't feel as cold to you as the aluminum ice tray in the freezer because

The tray conducts heat away more quickly

What causes a vehicle to accelerate?

a net force

When a solid is changed to a liquid state, the solid

absorbs energy

The air in this room has

all of these

A hypothesis in the field of science is

an educated guess

If an object moves with constant velocity, its acceleration must

be zero

If a net external force acts on a moving object, it will

change it's velocity

A coin and a ring of the same mass and diameter roll down an incline starting at the same time. The one to reach the bottom first will be the

coin

If an object undergoes a constant acceleration, the velocity of the object must,

continually change by the same amount each second

A 1 kg mass of copper requires 16 joules of heat energy to raise its temperature by 1. A 1 kg mass of tin requires 14 joules of heat energy to raise its temperature the same amount. You can conclude that:

copper has a higher heat capacity than tin

I spin my son on the merry-go-round at the playground. When he walks inward towards the center of the merry-go-round, the rotational inertia of the system will_____

decrease

If the radius of the earth somehow increased with no change in mass, your weight would

decrease

If the Earth expanded to twice its diameter with the same mass, its rotational speed would

decreased

A pizza chef tosses pizza dough in the air so that it spins. As it spins, its diameter slowly gets bigger. As this happens, its rotational speed ________

decreases

The centripetal force acting on an object in constant angular motion works to change its

direction of motion

As you rise from the bottom of a lake with your mouth closed, your lungs

expand as you rise

a newton is a measure of

force

A freight train rolls along a track with considerable momentum. If it rolls at the same speed, but has half as much mass, its momentum is

halved

The fact that the ocean water changes its temperature very little with the seasons is an indication that it has a

high heat capacity

One of the reasons that cooking pans are made of metals is because

high heat conductivity of metal

The boiling point of a liquid will_________ with decreasing altitude.

increase

I shove my sister off the Science Center with a horizontal speed of 20 m/s. As she falls, her velocity in the vertical direction

increases

When water at 4 degrees C is cooled its volume increases. When water at 3 degrees C is cooled, its volume

increases

An object stays at rest or in a state of constant motion because it has

inertia

Mass is our measure of an object's __________

inertia

A police officer's speed gun tells her your

instantaneous speed

Wisely, you don't use a metal coat hanger to roast your hotdogs at a wiener roast because the metal

is a good conductor of heat

When a car is struck by a train, the resulting acceleration of the train must be

less than the acceleration of the car

According to Newton the greater the distance between interacting objects, the

less the gravitational force between them by the square of the distance

I now take my pontoon from the freshwater of KY lake to the salt water of the Gulf of Mexico. My boat will now displace a ________volume of fluid as it floats.

lesser

Lighter colored clothes are worn in the desert areas of the globe because

lighter colors are poor absorbers of heat energy

When no forces act on moving objects their paths are normally

linear

Two objects rotate on a merry-go-round, one at r=1 m and the other at r=2m from the center. The object rotating at 1 m has less _______than the object at 2 m.

linear velocity

Different isotopes of an element on the periodic table are distinguished by their differing number of

neutrons

Absolute zero on the Kelvin scale is the temperature at which

no kinetic energy exists

Which of the following is a transverse wave?

ocean wave

The water in a pressure cooker can reach temperatures above its normal boiling point because

of the increased pressure on the fluid

Your mass is a scalar quantity because it has

only a magnitude

If the mass of an object doubled while its volume is cut in half, its density would

quadruple

My sister punches my face with her fist. Which experiences the greatest force?

same for both

Since the density of sea water is greater than the density of fresh water, the pressure is most at a depth of 3 m in

sea water

Which has a greater kinetic energy, a 5 kg mass traveling at 30 m/s or a 2.5 kg mass traveling at 60m/s?

the 2.5 kg mass

My 300 lb sister gets on my 2000 lb pontoon boat at KY lake. When she steps onto the boat,

the boat sinks to displace 300 lbs of water

It is correct to say that impulse is equal to

the change in momentum

As you walk across the floor of your apartment, what force enables you to walk forward?

the force of the floor on your foot

Which takes up more space, a kilogram of ice or a kilogram of aluminum?

the ice

As water evaporates from your skin outside the shower

the liquid absorbs heat from your skin

The roof of a convertible expands outward when going down the highway because

the moving air on top of the roof decreases the pressure there

Compared to a 1 kg bar of pure gold, the density of 2 g of pure gold is

the same

A 10 kg brick and a 1 kg book are dropped in a vacuum. The acceleration due to gravity on the 10 kg brick is

the same as the acceleration of the 1 kg book

The roofs of homes fly off in a tornado because

the velocity on top of the roofs was greater than the velocity on bottom

how many atoms are there in a water molecule, H2O

three

Non-metals are both poor heat conductors and poor electrical conductors because of the

tightly held nature of the electrons in non metal atoms

When a bimetallic strip made of brass and tin strips is heated (in class), the bar bends toward the brass strip because

tin expands more than brass

As a weather balloon rises higher in the atmosphere, its

volume increases