Forces
A person standing on a bridge has high...what type of energy?
Gravitational potential
A person bundjy jumping from a bridge has high...What kind of energy?
Kinetic energy
If you raise a pen into the air you are increasing its....
GPE
If you drop a pen and it falls this is transforming what...
GPE into Kinetic energy
Energy can only be transferred or transformed
What law is this part of?
What energies are used and produced by a Fan
Produces Kinetic (air movement)
heat
Sound
What are the wasted and useful energies produced by a radio alarm clock?
Light and Sound are useful
Heat is wasted
What kind of energy does water have if it is falling down a waterfall?
Both Kinetic and Gravitational potential
Which has more KE? A dog riding a skate board, flying down a hill at 40kph? A car rolling at 5kms
A Car has much greater mass, there fore much greater KE
What are 3 negative impacts of using fossil fuels
3 plausible impacts:
Finite resource
Pollution
Destroys environment to get or mine.
In a sanky diagram, arrows pointing down mean?
Wasted energy
In a sanky diagram, 300j points down, and 100js continues across.
Which value is the useful energy?
Calculate the GPE for:
a giant turtle weighs 60kg, is moving at 3m/s, and is 5m above the ground. What's it's GPE? gravity = 9.8
GPE = mgh
= 60x9.8x5
= 2940j
Calculate the KE: A Potato is breaking records moving at 46m/s. It weighs 1.3kg. It is 8m above the ground
Ke = 0.5 x M x V^2
= 0.5 x 1.3 x 46^2
= 1375.4j
What is the entire Law of Conservation?
Energy is never created or destroyed, only transferred or transformed.
What is the full energy chain for a Tv?
Input, outputs, useful and wasted?
Input is electricity. Output is Light, Heat, Sound,
Sound and light are useful. Heat is wasted
Eff = useful / input x 100
= 30/100 x 100
= 30%
If energy is never 'destroyed' explain what happens when I burn wood into ash?
Heat, light, sound are released, gasses are produced, ash remains
If Oliver does an inverted barrel roll in a jet moving at 3900m/s and his total mas is 6767kg, what is his KE?
Ke = 0.5 x 6767 x 39^2
=514,630,350j
514 Million
What are 3 advantages of renewable energies?
Good for the environment
Not fossil fuels
Renewable once built
Explain the energy chain for a Hair Dryer. Input energy, transform or transformation, what is useful, what is wasted?
Input: electricity
Energy is transformed into Heat, Sound, Kinetic and light (the element glows)
Only the heat and Kinetic is useful.
Which vehicle is more efficient, A or B. Vehicle A: used 140j to create 84J of kinetic and 30J heat, the rest is sound. Vehicle B: used 186J to create 115J of kinetic and 40J heat, the rest us sound
Divide the useful by the input energy x 100
84/140*100 = 60%
115/186*100 = 61.8%
A dog falling from space to earth has 14567J of Mechanical energy. 45% of this is K.E. the rest is GPE. how many Joules is the GPE?
14567*0.55 = 8011.85j
A Cat on a rocket going to space has 98750J of Mechanical energy. The GPE is 23,200j. How many joules is his K.E?
98750j-23200 = 75550j of K.E
If you had to recommend a new power plant for this area (not coal), which kind would you recommend. Give 3 reasons why
Renewable, 3 plausible reasons.