Kinetic Energy
What is the definition of kinetic energy?
the energy in the form of motion
or energy due to motion
What is the definition of potential energy?
Stored energy
What is the formula for work?
Work = force x distance
My dog pulls her toy with 30 N of force for 3 meters. How much work did she do?
30 x 3 = 90 J
Which would have more kinetic energy? A cheetah sleeping or a dog running?
dog running
Which would have more potential energy? A rock on top of the school, or a rock sitting in my desk?
Rock on top of the school
I pushed on my couch with 55 N of force but it did not move. Was any work done and why?
No because it did not move
What unit is power recorded in?
Watts
My 2 kg cat sits on the fence that is 2 meters high. What is her potential energy?
Pe = 2 x 9.8 x 2 = 39.2 J
What is the formula of kinetic energy?
Ke = 1/2 mv2
What is the formula for potential energy? And what does G = ?
Pe = mgh
g = 9.8
What unit is force recorded in?
Newtons (N)
more
A 2000 kg car is moving 5 m/s. What is their kinetic energy?
Ke = 1/2 (2000) (52) = 25,000 J
Does Kinetic Energy depend more on speed or mass?
speed (velocity)
What is the unit for potential energy?
Joules
I am pushing a boulder up a hill but I am too weak and it rolls backwards on me. Did I do any work on the boulder and why?
No, because the movement was not in the direction of the force.
Which requires more power? Running up the stairs or walking up the stairs and why?
running up the stairs because it takes less time and you have to work harder for it.
A 25 kg dog is 3 meters high in a tree.
A 4 kg cat sits 30 m high in a tree.
Who has more potential energy?
Pe= 25 x 9.8 x 3 = 735 J
Pe = 4 x 9.8 x 1176 J
Cat has more potential energy
What is the relationship between kinetic energy and potential energy? (what happens if kinetic energy goes up)
They are inversely related. They are opposites
Kinetic energy goes up, potential energy goes down.
Me and my chicken are both sitting on top of the shed. Who would have more potential energy and WHY?
Me because I have more mass
The distance movement must be in the direction of the force for work to have been done. (true or false)
true
I push my car 5 meters with 10 Newtons of force over 25 seconds. How much power did I use?
2 watts