Kinetic and Potential Energy Stores

Question 1

If anything is moving, what energy store is the energy in?

Answer 1

Kinetic

Question 2

What is the equation for kinetic energy?

Answer 2

Kinetic energy =

0.5 x Mass x (Speed)²

Question 3

What is the symbol equation for kinetic energy?

Answer 3

Ek = 0.5 m x (v)²

J) (Kg) (m/s

Question 4

When is energy transferred to an object’s kinetic energy store?

Answer 4

Energy is transferred to when an object speeds up, and away when an object slows down

Question 5

What factors affect the energy in an objects kinetic energy store?

Answer 5

The object’s mass and speed. The greater the mass and speed, the more kinetic energy

Question 6

What is the equation for gravitational potential energy?

Answer 6

GPE =

Mass x Gravitational Field Strength x Height

Question 7

What is the symbol equation for gravitational potential energy?

Answer 7

Ep = m x g x h

J) (Kg) (m/s²) (m

Question 8

What is the gravitational field strength on earth?

Answer 8

9.8N/Kg

Question 9

When is an object’s energy transferred to the gravitational potential energy store?

Answer 9

When an object is lifted, as it requires work

Question 10

What factors affect the amount of energy in a gravitational potential energy store?

Answer 10

The object’s mass, height, and strength of the gravitational field an object is in (9.8)

Question 11

When an object falls, what is its gravitational potential energy transferred into?

Answer 11

Kinetic energy

Question 12

What is the equation for elastic potential energy?

Answer 12

Elastic Potential =

0.5 x Spring Constant x (Extension)²

Question 13

What is the symbol equation for elastic potential?

Answer 13

F = 0.5 x k x (e)²

J) (N/m) (m

Question 14

What transfers an energy to an object’s elastic potential store?

Answer 14

Stretching/Squashing an object

Question 15

What is Hooke’s law?

Answer 15

The strain in a solid is proportional to the applied stress within the elastic limit of that solid

Question 16

What is the limit of proportionality?

Answer 16

• The point where Hooke’s law no longer exists

- The stretched material will no longer return to its original length when force is removed

Question 17

EXAMPLE 1

What happens when you throw a ball upwards?

Answer 17

• Initial force is exerted by a person
• Work is done
• Energy is transferred from the chemical store (ARM) to the kinetic store (ARM and BALL)

Question 18

EXAMPLE 2

What happens when a ball is dropped?

Answer 18

• Gravity does the work

- Energy is transferred from the gravitational store (BALL) to the kinetic store (BALL)

Question 19

EXAMPLE 3

What happens when a car brakes?

Answer 19

• Friction does the work

- As it slows down, energy transfers from the kinetic store (WHEEL) to the thermal store (SURROUNDINGS)