Deck 3: Energy: Why Must Animals Eat to Stay Alive

Question 1

From a physicist's point of view, in which of the following cases has significant work been done?

A) You try to pull your car out of ditch, but it doesn't budge.
B) Your brother throws his dirty clothes on the floor.
C) Your mother holds a sleeping baby.
D) You review for a test by imagining the questions.
E) Your father tries unsuccessfully to open a jar.

Answer 1

B

Question 2

Which of the following is equivalent to one horsepower?

A) 1000 kWh
B) 0.75 joules
C) 1200 ft-lbs per hour
D) 550 ft-lbs per second
E) 1100 ft-lbs per minute

Answer 2

D

Question 3

A stalled car is pushed to the top of a hill, allowed to roll down the hill and started by "clutch-popping" (turning the key while releasing the clutch rapidly). At which point did the car have the greatest amount of potential gravitational energy?

A) at the bottom of the hill
B) at the top of the hill
C) when restarted using the key and clutch
D) being pushed to the top of the hill
E) as it was rolling down the hill

Answer 3

B

Question 4

Stretching a rubber band and shooting it across the room is an example of releasing:

A) electrical potential energy.
B) kinetic energy.
C) chemical energy.
D) heat energy.
E) elastic potential energy.

Question 5

What kind of energy does a person experience during skydiving?

A) potential gravitational energy
B) potential energy
C) chemical energy
D) heat energy
E) kinetic energy

Question 6

What kind of energy does the pounding of ocean surf demonstrate?

A) kinetic energy
B) potential energy
C) sound energy
D) heat energy
E) mechanical energy

Question 7

James Watt designed experiments in horsepower to:

A) assist miners in removing ore.
B) calculate the velocity of a water pump.
C) quantify the energy generated by a horse in mines.
D) invent the steam engine.
E) assess the health of horses.

Question 8

When a meteorite hits Earth, heat is generated. Which of the following statements best describes this process?

A) Gravitational potential energy is converted into heat.
B) Electrical potential energy is converted into heat.
C) Chemical energy is converted into heat.
D) Magnetic energy is converted into heat.
E) Elastic potential energy is converted into heat.

Question 9

Lighting a fire with a match uses which kinds of energy?

A) chemical and kinetic
B) electrical and chemical
C) kinetic and heat
D) chemical and electrical
E) radioactive and potential

Question 10

What did James Prescott Joule discover about heat?

A) Heat is a form of energy.
B) Potential energy equals heat.
C) Calories should be limited to energy required.
D) Brass tools work better under water.
E) Horses expend energy at a rate of 550 foot-pound/second.

Question 11

The conservation law in science states that:

A) our natural resources are scarce.
B) once energy is used, it is lost to the system.
C) fossil fuels are an important energy source.
D) conservation will save fossil fuels.
E) the energy in an isolated system stays the same.

Question 12

The watt value printed on a light bulb tells the amount of energy the light bulb is using in joules per second. Which one of the following light bulbs is using the most energy?

A) 100-watt bulb that burns for twenty minutes
B) 75-watt bulb that burns for thirty minutes
C) 60-watt bulb that burns for one hour
D) 40-watt bulb that burns for two hours
E) 25-watt bulb left on for three hours

Question 13

Which of the following is a rate?

A) joule
B) foot-pound
C) power
D) energy
E) newton

Question 14

The first law of thermodynamics states:

A) in a freefall, energy is lost.
B) the sum of energy in an isolated system decreases over time.
C) a moving object will continue moving in a straight line unless acted on by an unbalanced force.
D) while the kind of energy in a closed system can change, the total amount cannot.
E) the approximate amount of energy you spend every day is equal to the force exerted over distance.

Question 15

Thermal energy is measured in units of:

A) joules/second.
B) calories.
C) watts.
D) foot-pounds.
E) meters/second.

Question 16

Energy can be stored in a flashlight battery as:

A) electrical energy.
B) chemical potential energy.
C) heat energy.
D) gravitational potential energy.
E) electromagnetic energy.

Question 17

The energy stored in all fossil fuels was originally in:

A) dinosaur bones.
B) meteors.
C) Earth's ocean.
D) uranium deposits.
E) the Sun.

Question 18

All popular weight loss diets are based on:

A) the conservation law.
B) increasing the exercise you do each day.
C) the first law of thermodynamics.
D) increasing protein intake.
E) decreasing the exercise you do each day.

Question 19

Which of the following balls would have the greatest amount of kinetic energy if they are all traveling at 10 m/s?

A) baseball
B) ping pong ball
C) bowling ball
D) soccer ball
E) basketball

Question 20

Which of the following organisms is at the first trophic level?

A) cow
B) killer whale
C) human
D) bacteria
E) plants

Question 21

Compare the rate of global fossil fuel consumption to the rate of production of fossil fuel from organic materials.

Question 22

Explain how mass can be converted to energy.

Question 23

Discuss the scientific argument about the age of the Earth that took place during the late 1800s between the physicists, the biologists, and the geologists.

Question 24

How does Einstein's famous equation, E = mc², relate to the energy needs of the world?

Question 25

What would be the ecological impact if the first trophic level were eliminated?

Question 26

Which of the following has the greatest amount of gravitational potential energy?

A) a case of books sitting on an end table
B) a bowling ball released for the strike
C) one diver at the highest point of the dive
D) a brick at the top of the Empire State Building
E) a hawk diving for its prey

Question 27

Every object at rest contains potential energy equivalent to the product of its __________ times a constant, which is __________.

A) energy; speed of the object
B) mass; speed of light
C) mass; speed of light squared
D) mass squared; speed of light squared
E) energy; speed of object squared

Question 28

What is the difference between food calories and a calorie as defined by physicists?

Question 29

What is a foot-pound?

Question 30

Which object carries the greatest amount of kinetic energy?

A) 250-gram baseball hit at 50 meters/second
B) 300-gram baseball traveling at 50 meters/second
C) 4-kilogram bowling ball traveling at 7 meters per second
D) 4-kilogram bowling ball traveling at 10 meters per second
E) a 120-gram tennis ball served at 50 meters/second

Question 31

Potential energy is defined as:

A) mass times height times gravity.
B) mass times speed times gravity.
C) mass times gravity times energy.
D) meters times heat times gravity.
E) meters times time times energy.

Question 32

Define work and give three examples.

Question 33

Construct an energy flow path from the Sun to turning on the ignition of a car.

Question 34

How would your weight change if you added the calorie equivalent of one canned soda to each of your meals and all other variables about your diet were held constant?

Question 35

What are the main problems with using solar energy?

Question 36

Compare and contrast an open system and a closed system. To which type of system does the first law of thermodynamics apply?

Question 37

Define joule and give its proper units.

Question 38

The top of the Earth's atmosphere receives 1.79 X 10¹⁷ joules of energy per second; however less than half of that amount ever reaches the ground. Where is this energy lost?

Question 39

To calculate how many calories your body needs to maintain your current weight for a week, you need to know all of the following except:

A) your current weight.
B) the approximate amount of energy you expend each day.
C) the number of calories used daily for normal body maintenance.
D) the recommended weight for your height.
E) the number of days in the week.

Question 40

What is power, in physical terms?

Question 41

Why is the transfer of energy so inefficient when it moves between trophic levels?

Question 42

What is the main difference in diet for organisms at the second trophic level versus the third trophic level?

Question 43

How do hybrid cars work?

Question 44

If you can make your hands warmer by rubbing them together, can you make two ice cubes warmer by rubbing them together? Explain.

Question 45

Paleontologists have recently proposed that dinosaurs were warm-blooded. Discuss this viewpoint using trophic level principles.

Question 46

Is more work expended for a 100 kg player to walk across a football field as opposed to a 50 kg female cheerleader who travels the same distance? Explain.

Question 47

What are the problems of converting from a fossil-fuel based society to one that relies on alternative energy sources? Explain.

Question 48

How did the discovery of radioactivity affect the controversy between two competing theories about the age of the Earth?

Question 49

Describe the time that is left before depletion of high-grade crude oil and the cleanest burning coal deposits.

Question 50

Under what circumstances could Earth be considered a closed system?