physics quiz #3

name some things that happen to the sunlight that prevent some of it from being absorbed by the Earth's surface

- reflected back into space -absorbed by plants, used for wind patterns, or helps water through hydraulic cycle - sun radiation from space is reflected by clouds -excess solar radiation is absorbed by clouds - atmospheric dust absorbs and reflects solar radiation - reflected back into space from Earth's surface -absorbed by gases in the atmosphere

A 30.0kg child on a trampoline jumps vertically into the air at an initial speed of 1.60m/s. Calculate how high the child will rise.

0.130 m

The potential energy of an apple is 6.00J. If the apple is 3.00m high, what is its' mass?

0.204 kg

an average force of 15 N used to compress a spring by 2.5 cm. the potential energy stored in the compression spring is?

0.38 J

A catcher picks up a baseball from the ground. If the force on the ball is 0.070N and 0.040J of work is done to lift the ball, how far does the catcher lift the ball?

0.571 m

A coconut is growing 10m above the ground in its palm tree. The tree is just at the edge of a cliff that is 15m above the sea. If the coconut has 196J of potential energy in relation to the sea, what is the mass of the coconut?

0.80 kg

An astronaut dropped a hammer (m = 1.32kg) from a height of 1.60m while walking on the moon. If the hammer had 3.42 J of gravitational energy before being dropped, the acceleration due to gravity on the moon would be?

1.62 m/s2

When a 16 kg child slides down a playground slide, she reached a speed of 5.8 m/s at the bottom. What was the height of the slide? (Assume no friction)

1.7 m

Suppose that you pedalled up a hill and gained a vertical distance of 25m. You turned around and coasted down the hill. If the combined mass of yourself and your bicycle is 68kg and the efficiency of this energy transformation as 34%, what speed were you coasting at when you reached the bottom of the hill?

13 m/s

A 102 kg soapbox derby car starts at the top of a hill. The starting point is a vertical distance of 40.0 m higher than the finish line. The car is going 11 m/s when it crosses the finish line. With what efficiency did the car convert its gravitational potential energy into kinetic energy?

15%

A 10.0 kg water balloon is dropped from a height of 12.0m. Calculate the speed of the balloon just before it hits the ground.

15.3 m/s

An arrow is drawn back in bow. 22.8J of elastic potential energy are stored in the stretched string and then the string is released. The arrow reaches a maximum height of 78m before falling back to the ground. If the bow is 62% efficiency in transforming the elastic potential energy into gravitational potential energy, what is the mass of the arrow?

18 g

Renatta is out with her friends when her car runs out of gas. They apply a cumulative force of 1080N to push the car 218m to the nearest fuel station. How much energy is gained by the car?

2.35x105 J

Using the graph below, determine the work done to move an object 30m.

2.5x103 J

Lamar Grant became the first man to deadlift five times his own body weight in 1985. Deadlifting involves raising a loaded barbell from the floor to a position above the head with outstretched arms. Determine the energy gained by the barbell when Lamar lifts 300kg to a height of 0.90m above the ground.

2.6x103 J

The kinetic energy of a 2.0kg droid is 5.00X102J. The speed of the droid is?

22 m/s

A bobcat uses 393 kJ of chemical potential energy stored in the fuel to lift 2750 kg of dirt 3.2 m straight up, to dump it into a truck. What was the efficiency of the bobcat in converting chemical potential energy into gravitational potential energy of the dirt?

22%

what is the earth's angle of inclination

23.5 degrees

Missy Diwater, the former platform diver for the Ringling Brother's Circus had a kinetic energy of 15 000J just prior to hitting the bucket of water. If Missy's mass is 50kg, then what was her speed prior to hitting the water?

24 m/s

A child does 405J of work to pull a sled up a snow-covered hill. If she walks a distance of 15m up the hill, what force does she exert on the sled?

27 N

A rocket uses 4000.0 J of chemical potential energy stored in the fuel while shooting the 0.55 kg rocket straight up into the air. The rocket reaches a height of 23 m. What was the efficiency of the rocket in transforming the chemical potential energy of the fuel into gravitational potential energy?

3.1%

A 20.0g dart is fired from a dart gun with a horizontal speed of 4.10m/s. The total mechanical energy of the dart is 0.481J. The gravitational potential energy of the dart is?

3.13x10-1 J

The smallest bird is the Cuban bee hummingbird. If this bird did 0.00100J of work by exerting a force of 0.000300N, how many meters did it fly?

3.3333 m

Assume that the force of the golf club acts parallel to the motion of the ball and that the club is in contact with the ball for a distance of 0.010m. The average force applied to the golf ball by the club, in the previous question, is?

3.8x103 N

The potential energy of a 40.0kg cannon ball is 1.40X104J. How high was the cannon ball to have this much potential energy?

35.7 m

A 0.60kg basketball is dropped out of a window that is 6.1m above the ground. What is the gravitational potential energy of the basketball, relative the ground?

36 J

When a 0.045kg golf ball takes off after being hit, its speed is 41m/s. How much work is done on the ball by the club?

38 J

The work done to push a shopping cart with a force of 70N for 5.6m is?

392 J

A bus travelling at a speed of 35.0km/h has 2.00 X 10 6 J of kinetic energy. The mass of the bus is?

4.23x104 kg

There is a rooster-shaped weather vane at the top of a tower. If the weather vane has a mass of 15kg and 6600J of potential energy, how high is the tower?

45 m

Mary expends 576J of energy to run home with a speed of 4.9m/s. Mary's mass is?

47.98 kg

When a 100.0 W light bulb is on for 1.0 h, it uses 360 kJ of electrical energy. During that time, the light bulb emits 19 kJ of light. What is the efficiency of the light bulb in transforming electrical energy into light energy?

5.3%

A safe is hurled down from the top of a 1.3X102m building. What is its velocity as it hits the ground?

51 m/s

A speed skier with a mass of 67kg reaches a speed of 58m/s when passing the first timing point. If that point is a vertical distance of 280m lower than the starting point, what was the efficiency of the transformation of the skier's gravitational potential energy to kinetic energy?

61 %

A 0.300kg baseball is thrown in a straight line through the air. At a height of 2.50m above the surface of Earth, it has a speed of 20.0m/s. The total mechanical energy of the baseball is

67.4 J

A bowling ball is dropped from the top of a building. If it hits the ground with a speed of 37.0m/s, how tall was the building?

69.8 m

A painter uses 1.93kJ of mechanical energy to pull on a rope and lift a 20.0kg paint barrel. If the efficiency of the rope and pulley system is 76%, how high did the painter lift the barrel?

7.5x 10-3 kj = 7.5 J

There is a bell at the top of a tower that is 45m high. The bell has a mass of 19kg. Determine the gravitational potential energy of the bell.

8.4x103J

Wile E. Coyote sets up a pulley to lift a gigantic boulder over a valley highway in an attempt to squish the Roadrunner. Wile E. Coyote puts 3402 J of energy into the pulley while the pulley does 2938 J of work. Calculate the efficiency of the pulley.

86.36 %

An electric motor uses 670 kJ of electrical energy to generate 595 kJ of mechanical kinetic energy. What is the efficiency of the motor?

88.9%

A construction worker drops a 2.00kg hammer from a roof. When the hammer is 50.0m above the ground, it has a total mechanical energy of 1.88X103 J. The kinetic energy of the hammer is?

899 J

A forklift lifts a load a distance of 2.0m above the ground. If the work done by the forklift is 180 000J, the force required is?

9.0x 104 N

A car is travelling with a velocity of 40m/s and has a mass of 1120kg. The kinetic energy of the car is?

9.0x105 J

You serve a volleyball with a mass of 2.1kg. The ball leaves your hand with a speed of 30m/s. The kinetic energy of the volleyball is?

9.5x102 J

A microwave oven has an efficiency of 47%. In one minute, the oven can add 42.4kJ of thermal energy to a mug of hot chocolate. What is the total input energy to the oven during this time?

90 kJ

The Millennium Force is the highest roller coaster in North America. It reaches a maximum height of 94.5 m. The total mass of a roller coaster car and its passengers is 1380 kg. The speed of the roller coaster is 41.1 m/s at its lowest point on the tracks. What is the efficiency of the roller coaster in transforming gravitational potential energy into kinetic energy?

91.1%

amount of incoming radiation is ____ to the amount of outgoing radiation

=

weight

A measure of the force of gravity on an object

force

A push or pull exerted on an object. vector quantity. measured in newtons

Solar energy

Almost all of the energy on Earth is from the sun in electromagnetic radiation

low albedo

Dark-coloured surfaces absorb sunlight such as forest soil

winter solstice

December 21, the Earth is titled the furthest away from the sun and is the shortest day of the year with least amount of sunlight

latitude

Earth's curvature causes solar energy to become distributed unequally

First law of thermodynamics

Energy can be transferred and transformed, but it cannot be created or destroyed, including heat

work

Force exerted on an object that causes it to move. transfer of mechanical energy from one object to another

Summer Solstice

June 21, the earth is titled closest to the sun, is the longest day of the year with most sunlight

Spring equinox

March 21, number of daylight hours is equal to number of night hours, the Earth's axis is perpendicular to Earth's rotation.

Longest wave

Radio waves

Electromagnetic spectrum

Refers to the radiation waves released from stars

Fall equinox

September 22, number of day hours is equal to number of night hours

James Joule's experiment

The force of gravity on the weight causes the weight to fall toward the ground. While it is falling, the weight pulls on the string and turns the drum, which stirs the water. Joule measured the force that gravity exerted on the weight, the distance that the weight fell, and the temperature change of the water. He determined the amount of work done on the water and related it to the change in the energy of the water.

why do we have seasons

The tilt of the Earth's axis

The diagram of the pendulum illustrates a swinging bob at various stages. Assume that the system is frictionless. The mass of the bob is 1.00 kg and the distance h=0.200 m. Answer the questions that follow: a)What is the potential energy of the bob at position A? b) What is the kinetic energy at position A? Why? c)What is the kinetic energy of the bob at position C? Give your answer in Joules. Explain how you found your answer. d)Calculate the velocity at which the bob would be going at position C. e)At position B, the bob is located at ½ h from the base line running through position C. What is the potential energy of the bob at position B? f)What is the kinetic energy of the bob at position B? g)Calculate the velocity at which the bob would be going at position B. h)In the real world, the pendulum cannot swing forever; in other words, it cannot be a perpetual motion machine. Explain why that is so.

a) 1.96 J b)0 b/c v=0 c)1.96 J b/c of law of conservation d) 1.98 m/s e) 0.981 J f) 0.981 J b/c law of conservation g)1.40 m/s h) 2nd law of thermodynamics

An average force of 100.0N is required to pull back a bow string a distance of 0.500m. The bow is aimed vertically. a)What is the work done on the bow? b)How much potential energy is stored in the bow? c)How much kinetic energy does the arrow have at the instant it is released from the bow? d) What will be the potential energy of the arrow at its highest position in its flight in the air?

a) 50.0J b) 50.0J c) 50.0J d) 50.0J

a physics textbook has a mass of 2.2 kg a) what is the weight of the textbook on Earth? b) what is the weight of the textbook on mars (3.7 m/s2) c) if the textbook weighs 19.6 N on Venus, what is the acceleration due to gravity on Venus

a)22 N b)8.1 N c)8.9 m/s2

clouds absorb

absorb solar radiation that is emitted from the Earth's surface

factors affecting radiation

angle of inclination, latitude, albedo

list the following in order of increasing albedo: bare soil, desert sand, fresh snow, green grass

bare soil, green grass, desert sand, fresh snow

absorption and reflection occurs in all three components of the _____

biosphere

Each of three students, A, B and C pushes a box 4m along a frictionless floor. The boxes are identical and all the boxes are initially at rest. Which student does more work to move his box?

c

atmospheric dust albedo

can reflect and absorb incoming solar radiation

hemisphere of the Earth that is tilted away from the sun will experience

colder temp. and will be winter

purpose of a machine

convert the initial energy added into the type of energy need to do the work that you want done

Frequency

describes how many waves per second a wavelength per second

Thermodynamics

describes how thermal energy is converted to and from other forms of energy and how it affects matter.

second law of thermodynamics

direction of energy flow in a natural process. states that heat naturally flows from a warmer object to a colder. work must be done to remove heat from the objects that are cooler than the surroundings. it also states that the more energy is transferred and transformed the more of it is wasted

mechanical energy

energy is due to the motion and position of an object

net surplus

equator

describe how a locations' latitude affects the amount of radiant energy it receives

equator regions receive more solar energy because the sun's rays hit the surface more directly, so incoming radiation is concentrated over a small area and more energy is absorbed. Polar regions receive less solar energy because the sun's rays spread out over a larger area.

James Joule

first law of thermodynamics. performed accurate measurement relating mechanical energy to heat.

Shortest wave

gamma rays

Short wavelengths

gamma rays, x-rays, ultraviolet.

3 types of potential energy

gravitational, elastic, chemical

when the sun rays hit the Earth at an angle, the amount of solar radiation is more spread out over a larger area, so colder. This is because of

higher and lower latitudes

efficiency

is a measurement of how effectively a machine converts energy input into useful energy output

insolation

is the amount of solar energy received by the Earth's surface

angle of inclination

is the angle at which the Earth's poles are tilted from the perpendicular axis

net radiation budget

is the difference between the amount of incoming radiation and outgoing radiation re-emitted by the Earth's surface and atmosphere

albedo

is the percent a surface reflects solar radiation

high albedo

light-coloured surfaces reflect sunlight such as snow and sand

equator albedo

lower albedo and higher insolation, so more incoming radiation than outgoing radiation

explain the difference between weight and mass

mass is the amount of matter in an object and doesn't change while weight is the force of gravity on the mass of an object and does change

Wavelength

measures the length of a wave in meters

equator

middle of the earth and is where sun rays hit the Earth most directly and the solar radiation is concentrated in one area, so warmer

Short wavelengths =?

more energy

3 conditions for work

movement, force, force and distance(m) in same direction

three major climate regions

polar (arctic), temperate, tropical

Identify Earth's three main climate zones and describe the sun rays and each zone

polar(arctic): the sun's rays hit the surface at an angle and spread out a lot over an area so temp. is colder. Temperate: the sun's rays spread out compared to the tropical zone but not as much as polar, so medium temp. Tropical: the sun's rays hit directly on the surface so not as spread out so hotter temp.

net deficit

poles

explain the meaning of the term "radiation budget." explain why it is important that Earth balance its radiation budget.

radiation budget describes the difference between the amount of incoming and outgoing solar radiation. The balance is important so that the Earth's average temp. remains constant. If the radiation budget were to become unbalanced, the average temp. of the Earth would either increase or decrease

Long wavelengths

radio waves, microwaves, infrared radiation, visible light

clouds reflect

reflect some of the incoming solar radiation back into space, so that is why it is cooler on a cloudy day

The reflected radiation goes back into ____ or is absorbed elsewhere in the ____

space, biosphere

potential energy

stored energy that results from the position or shape of an object

energy

the ability to do work, measured in joules

how does the angle between Earth's axis and the plane of its revolution around the sun affect seasons?

the angle of inclination of the Earth is 23.5 degrees and is what causes seasons. northern hemisphere when tilted near the sun will experience warmer temperatures (summer), and when tilted away will experience colder temperatures (winter)

Net radiation balance

the earth trues to maintain an energy balance and a temperature balance by radiating as much energy into space as it absorbs from the sun

kinetic energy

the energy an object has due to its motion

law of conservation of energy

the law that states that energy cannot be created or destroyed but can be changed from one form to another

polar regions albedo

there is less insolation and higher albedo, so more outgoing radiation than incoming radiation

the absorbed solar energy can be re-emitted as ____ ____ used to move water through the _____ _____, create _____ ____, or used by plants for ______

thermal energy, hydraulic cycle, wind patterns, photosynthesis

hemisphere of the Earth that is tilted toward the sun will experience

warmer temp. and will be summer

net radiation and latitude

while the net radiation is balanced, the warming of the earth is unequal