P1 - Conservation and Dissipation of Energy - P1.1, =======> P1.5 Done

Question 1

What are some examples of chemical energy stores?

Answer 1

Fuels, foods, or the chemicals found in batteries

Question 2

What is thermal energy?

Answer 2

Energy that substance has due to its temperature

Question 3

What is gravitational potential energy?

Answer 3

Energy that a substance has due to its position, such as an object above the ground

Question 4

How can energy be transferred?

Answer 4

Through waves, heating, electric current, or a force when it moves an object

Question 5

What happens (in terms of energy) when an object falls?

Answer 5

It speeds up as its gravitational potential energy changes into kinetic energy

Question 6

What does a closed system mean?

Answer 6

Where there is no net change to the energy stored in the system

Question 7

What is a system?

Answer 7

An object or a group of objects

Question 8

What is the main rule in relation to energy that you must always remember?

Answer 8

It cannot be created or destroyed

Question 9

Why does a pendulum fail to continue swinging?

Answer 9

As it is not in a closed system and air resistance is acting on the pendulum - slowing it down and eventually stopping it

Question 10

When is a practical application of you using work done to your advantage?

Answer 10

When you work out

Question 11

What is work done?

Answer 11

The energy transferred to an object

Question 12

Name two times that friction comes into effect practically?

Answer 12

Brake plates on cars, asteroids entering the atmosphere, and when you rub your hands together vigorously

Question 13

What type of energy does friction often cause to be released?

Answer 13

Thermal or heat energy

Question 14

What is the equation for work done?

Answer 14

Work done, W (J) = Force applied, F (N) x Distance moved along the line of action of the force, s (m)

Question 15

What is the type of energy store that increases when you lift something up?

Answer 15

Gravitational potential energy

Question 16

How are weight and mass different?

Answer 16

Weight is the amount of force needed to lift an object, whereas mass is the amount of particles in something defines by kilograms - weight is in Newtons

Question 17

What is the equation that links change in gravitational potential store and weight?

Answer 17

Change in an objects gravitational potential store, (J) = Weight (N) x Change of height (m)

Question 18

Why can astronauts lift things much easier on the moon?

Answer 18

As the gravitational field of the moon is such weaker and therefore the force needed to lift objects is less. (It is about a sixth weaker than on Earth)

Question 19

What is the multiplier to find the weight of objects on Earth?

Answer 19

9.8x (the gravitational field strength multiplies the mass by 9.8 times in order to lift something, it is 9.8N per kilogram)

Question 20

What is the equation that links change in gravitational potential energy store and mass?

Answer 20

Change in an objects gravitational potential store, (J) = Mass, (Kg) x Gravitational field strength, (N/kg) x Change in height, (m)

Question 21

What does the Greek letter Delta (aka the triangle) mean in scientific equations?

Answer 21

Change in …………. (Whatever it is followed by)

Question 22

What two things does the kinetic energy of an object depend on?

Answer 22

Its mass and speed

Question 23

If the speed of an object increases, its kinetic energy ……………?

Answer 23

Also increases

Question 24

What is the equation that links kinetic energy and mass?

Answer 24

Kinetic energy, (J) = 1/2 x Mass, (kg) x speed^2 (m/s)

Question 25

What is the equation that links elastic potential energy and the spring constant?

Answer 25

Elastic potential energy, (J) = 1/2 x spring constant, (N/m) x Extension^2 (m^2)