SCIENCE FINAL unit 9

what is energy measured in

joules

127.Work may be measured using units of:

joules.

1 5 2 4 3 6 A marble rolls along a track with no friction. What is the sequence of positions from lowest kinetic energy to highest kinetic energy.

1,5,4,2,3,6

Sammys short walk 5 2 4 5 1 4 5 1 3333 4 5 1 Which segment does Sammy move the greatest distance back toward the point of origin

5

Sammys short walk 5 2 4 5 1 4 5 1 3333 4 5 1During this trial sammy move a specific amount of distance, some toward the motion detector and some away from it. Approximately what is the total distance sammy moved while going away from the point of origin? (just memorize)

1.6 m

101.If you do 500 joules of work using a force of 50 newtons, over what distance was the work accomplished?

10

109.How much power is necessary to do 50 joules of work in 5 seconds?

10 watts

Natalie lifts a 15kg rock onto a 1.5 meter high wall. What is the amount of potnetial energy she has?

220 joules

91.Atmospheric pressure is 100,000 N/m2 at sea level. The force exerted on a sheet of plywood 3.00 meters long and 0.750 meters wide on the ground is:

225,000 N

Jills short drive home - - - - ----- - - ----- - - - ------- - - ----- is jills acceleration between 10 and 14 seconds

25 mph

Jills short drive home - - - - ----- - - ----- - - - ------- - - ----- time is most likley represent the moment jill tuned her car around and started heading back home

42 seconds (almost peak)

How much kinetic energy does a 1000 kg car have when it is traveling at 30 m/s

450,000 J

a 1500 kg car accelerates along a flat track to a speed of 20 m/s. How much does its gravitational potential energy increase over the length of the track?

0 joules

Jills short drive home - - - - ----- - - ----- - - - ------- - - -----what is jills acceleration (m/s squared) between 10 and 14 seconds?

0 mph/s

Sammys short walk 5 2 4 5 1 4 5 1 3333 4 5 1 What is sammys average speed during segment 4?

0.1 m/s

How long does it take sammy to go five miles at a velocity of 25 miles per hour?

0.2 hours

134.If I measure the mass of my rocket to be 295g and I use a water volume of 1000mL, what is the mass(in kg) that I should include in the data table?

0.295 kg

98.Your teacher has given you an opaque plastic bottle that can hold a total of 25.0 mL. The bottle has been filled with a mystery substance and sealed. Use the table and information to answer the following questions. When you place the sealed plastic bottle in the tank of glycerin, what is the value for the buoyant force acting on the bottle? (Use Table 12-1 and/or the information below the table to answer this question.)

0.308 N

118.Calculate the speed of the object from the position vs. time graph shown below.

0.5 m/s

88.The density of a 14-gram cube of wood measuring 3.0 centimeters on an edge is:

0.51 g/cm3

Sammys short walk 5 2 4 5 1 4 5 1 3333 4 5 1 During which segments is sammy moving at almost constant speed away from the point of origin (o,o)

1 and 4

A car having a mass of 654 kg has a kinetic energy of 73400 J. What is the cars speed?

15 m/s

A .6 kilogram basketball balances on the rim of a basketball hoop that is 3 meters high. What is the basketball's potential energy

18 J

110.The efficiency of a modern bicycle is 95 percent. If you exert 200 joules in pedaling a bicycle on level ground, what is the work output?

190 joules

Sammys short walk 5 2 4 5 1 4 5 1 3333 4 5 1 At which segment is sammy moving back toward the point of origin?

2 and 5

Sammys short walk 5 2 4 5 1 4 5 1 3333 4 5 1When is sammys slope a negative numer

2 and 5

94.An automobile engine exerts a force of 500 newtons on a car to travel 4,000 meters. What is the amount of work done by the engine?

2,000,000 j

111.Running up a flight of stairs, Marita generates 450 watts of power. If it takes her 6 seconds to go up the stairs, the amount of work she does in running up the stairs is ____ joules.

2,700

Jills short drive home - - - - ----- - - ----- - - - ------- - - ----- what is jills acceleration (m/s squared) between 0 and 10 seconds?

2.5 mph/s

A rubber ball with a mass if 0.1kilogram is thrown straight up with a speed of 20 m/s. What is the height at which the ball travels? (Diagram)

20.4m

112.An electrical water heater raises the temperature of water by adding 8,000 joules of energy to the water in 40 seconds. What is the minimum power required by the water heater?

200 joules

If sammy can accelerate at 72.6 mi/hr/s, how fast will he be going after 3 seconds (assuming he starts at 0 m/s)

217.8 mi/hr

75. Natalie lifts a 15-kg rock from the ground onto a 1.5 meter high wall. What is the amount of potential energy she has given the rock?

220 j

95. Your teacher has given you an opaque plastic bottle that can hold a total of 25.0 mL. The bottle has been filled with a mystery substance and sealed. Use the table and information to answer the following questions. Your teacher instructs you to place your bottle into a displacement tank filled with olive oil. If the bottle floats, you should gently push down until the top of the bottle is even with the surface of the liquid. Approximately how many mL of liquid will be displaced by the bottle if you follow your teacher's instructions? (Use Table 12-1 and/or the information below the table to answer this question.)

25.0 mL

87.At 20.00°C, the density of copper is 8.900 g/cm3. If a section of copper pipe displaces 285.0 milliliters of water when dropped in a displacement tank, what is the mass of the pipe?

2537 g

76. How high would you need to lift a 2-kg bottle of soda to increase its potential energy by 500 joules?

25m

how high would you need to life a 2kg bottle of soda to increase its potential energy by 500 joules

25m

A biker increases her speed from 0 to 10 m/s in 5 seconds. What is her acceleration?

2m/s/s

Sammys short walk 5 2 4 5 1 4 5 1 3333 4 5 1 During which segment is sammy standing still

3

89.The volume of a 67.2-gram sample of platinum with a density of 21.5 g/cm3 is:

3.13 cm3

what is the kinetic energy of a go cart with a mass of 150 kilograms and a speed of 20 m/s

30,000 J

77.What is the kinetic energy of a go-cart with a mass of 150 kilograms and a speed of 20. m/s?

30000 J?

135.If the initial kinetic energy of my rocket is calculated to be 352 J, the potential energy at the apex must be:

352 J

How much potential energy is help by a 2kg can of paint on top of a 2 meter ladder

39.2

124."Every action force creates a reaction force that is equal in strength and opposite in direction." This statement summarizes Newton's:

3rd law of motion.

If you go twice as fast (speed increases by 2 fold) you kinetic energy becomes what?

4 times bigger

If you go twice as fast your kinetic energy becomes what?

4 times bigger

Kevin jumps straight up in the air to a height of 1 meter. at the top of his jump, he has a potential energy of 1000 j. If Kevins potential energy at the highest point of the jump is 1000 J what is his speed when he leaves the ground?

4.4 m/s

113.As fuel burns in a jet engine, it releases 40,000 joules of energy. Out of this, only 16,000 joules are available to do work. The efficiency of the engine is ____ percent.

40

93.Calculate the work needed to push a block with 4 newtons of force a distance of 10 meters.

40 j

131.If the initial velocity of your rocket is 10 m/s and its mass is 8kg, what is its initial kinetic energy?

400 J

103Jake, who weighs 680 newtons, climbs a 6 meter ladder in 8 seconds. What was Jake's power?

510 watts

If starting from a standstill, a skateboarder accelerates at a rate of 1.5m/s/s, what is his speed after 4 seconds?

6.0 m/s

Jills short drive home - - - - ----- - - ----- - - - ------- - - ----- What is jills average acceleration between 32 and 40 seconds

6.3 mph/s

someone travels 105 miles in 16 seconds, what their velocity

6.5 miles/sec

80.A bowler lifts her bowling ball a distance of 0.5 meters using 35 joules of energy. What is the mass of her bowling ball?

7 kg

104.A bowler lifts her bowling ball a distance of 0.5 meters using 35 joules of energy. If, on Earth, a 1.0 kilogram mass weighs 9.8 newtons, the mass of the bowling ball used by this bowler is about:

7 kilograms

102.Robert lifts a 150-newton bucket of water 0.5 meters in 3 seconds. What is the amount of work done on the bucket?

75j

108.An electric food processor uses 250 joules of electrical energy every second. Due to friction and other causes, the energy available to spin the blades to cut food is reduced to 200 joules per second. The efficiency of the food processor is:

80 percent.

114.If a machine's maximum power rating is 2,000 watts, how much work could it do in 40 seconds?

80,000 joules

115.Which of the following is NOT considered a simple machine?

Electric motor

132.Which of the following would be the best conclusion to draw from the graph below?

Height of the rocket increases with air pressure

When energy is transformed, what happens to the total amount of energy in the system?

It stays the same

133.The best way to get data for water volume vs. height would be to:

Keep all variables constant, change only water volume

117.What are the units of mechanical advantage?

Mechanical advantage has no units.

While sitting next to a camp fire, Kenai noticed several different forms of energy being transforme form potential chemical energy of the wood. Which form of energy would she not see in the campfire?

Nuclear

129.Which of the following improves the efficiency of a machine?

Reducing friction

130.In your floating clay boat lab, you used a block of clay to create a boat. Which of the following best describes why the boat floated, but the block did not?

The boat displaced more water than the block.

92.What does Archimedes' principle state?

The buoyant force acting on an object is equal to the weight of the fluid displaced by the object.

120.The tires on a car have grooves in them. How do these grooves affect the friction between the tires and the road during wet weather?

They increase friction.

When gasoline is used as a fuel in an automobile engine, several energy transformations take place. What is a statement that does NOT agree with the law of conservation of energy?

When gasoline is burned its energy is destroyed

125.Energy can be thought of as stored ____.

Work

13 km/hr/s squared is an example of a what quantity>

acceleration

Jills short drive home - - - - ----- - - ----- - - - ------- - - ----- When does jill stop moving

almost peak (40 sec)

116.In a machine, work output:

an be calculated by multiplying output force by output distance.

90.The measure of the upward force a fluid exerts on an object that is submerged is:

buoyancy

Refer to the diagram above (Sun->Apple Tree->Person Eating Apple) The arrow between the tree and te person represents the change from what?

chemical to mechanical energy

When a ball is thrown into the air, the potential energy gained must come from its kinetic energy. As the ball gains potential energy, its speed will

decrease

when a ball is thrown into the air, the potential energy gained must cine from its kinetic energy. As the ball gains potential energy, its speed will what?

decrease

83. When a ball is thrown into the air, the potential energy gained must come from its kinetic energy. As the ball gains potential energy, its speed will:

decreases

As a car rolls down a hill, it potential energy...

decreases

what slope will show velocity?

distance vs time

128.The measure of how effective a machine is in using energy to do work is called:

efficiency.

the ability of an object to change or cause changes is what?

energy

84.Which of the following use the same units of measurement?

energy and work

t/f Kinetic and potential energy are both forms of chemical energy

false, mechanical energy

Jills short drive home - - - - ----- - - ----- - - - ------- - - ----- when is jll moving at a constant velocity?

first incline (10-14 sec)

107.The work output of a machine:

is always less than the work input.

79.What happens to the energy stored in oil when you use it to heat your house?

it is converted to heat energy

is you create a distance vs time graph of a runner, what dos the line on the graph look like if the runner has a negative velocity?

it slopes down

78.When energy in a system is transformed, what happens to the total amount of energy in the system?

it stays the same

86.All of the following are units used to measure density EXCEPT:

kg/N

The brakes on an automobile become hot when they are used conintuously because?

kinetic energy is converted to thermal energy

What does kinetic energy depend on

mass and velocity

82.While sitting next to a campfire, Kenai noticed several different forms of energy being transformed from the potential chemical energy of the wood. Which form of energy would NOT be present in the campfire?

nuclear

The radiant energy given off by the sun is formed from what energy

nuclear

106.The efficiency of a machine is usually expressed in:

percent

An extended spring stores?

potential energy

As an object is raised to a higher position increases which type of energy

potential energy

(Sun->Apple Tree->Person Eating Apple) The arrow between the sun and the tree represents a change from what?

radiant to chemical energy

Jills short drive home - - - - ----- - - ----- - - - ------- - - -----When is jill slowing down

second to last decline (28-32 sec)

99Your teacher has given you an opaque plastic bottle that can hold a total of 25.0 mL. The bottle has been filled with a mystery substance and sealed. Use the table and information to answer the following questions. If the weight of the bottle with the mystery substance inside is 0.250 N, the bottle will:

sink in olive oil and glycerin.

85.In general, the most dense phase of matter on Earth is:

solid

(diagram) A ball is thrown from position 1 to a height of 3 meters (position 2) to give it potential energy. The ball then falls to position 3. Assuming there is no energy loss due to friction compare kinetic energy at position 1 with kinetic energy at position 3.

stays the same.

123.Newton's first law of motion is also known as:

the law of inertia

122.If the net force on a moving object is zero:

the object will not change direction or speed

100.If forces A, B and C are equal, the work done by the forces as they are exerted on the box is:

the same

81.Friction between two surfaces transforms energy of motion directly to:

thermal energy

126.t/fPower plants convert other sources of energy into usable electrical energy.

true

t/f Switching on the tv produces heat and sound energy

true

t/f The heat released by a burning candle is an example of thermal energy

true

10m/s is an example of a what quantity?

velocity

the main difference between speed and velocity is that what?

velocity includes direction

what graph will show acceleration

velocity vs time

Energy can be thought of as stored what?

work

105.Efficiency is defined as the ratio of:

work output to work input