KE Relationship
Two carts move at the same speed. Cart A has twice the mass of Cart B. Compare their kinetic energies.
What is Cart A has twice the kinetic energy of Cart B?
“🎵 When I was a young boy
My father took me into the city
To see a marching band
He said, ‘Son, when you grow up
Would you be the savior of the broken
The beaten and the damned? 🎵’”
What kind of energy is this an example of?
Sound energy
What is Conservation of Energy?
Conservation of Energy is a law that states that energy can’t be created or destroyed.
Energy is often detected through changes such as motion, heat, light, or sound. What do these observations indicate?
What is energy is present or being transferred?
Astronauts appear to float inside the International Space Station. Is gravity absent there, and why or why not?
What is gravity is still present; astronauts are in continuous free fall while orbiting Earth?
When you add friction into an equation what type of energy is present and how does it interact with kinetic energy.
When you add friction to an equation thermal energy is present and it interacts with KE because KE gets transferred into thermal energy.
What is the formula for GPE?
GPE=mgh.
At the bottom of a hill, an object has maximum speed. Why does this not violate conservation of energy?
What is potential energy was converted into kinetic energy?
Why does increasing speed affect kinetic energy more than increasing mass?
What is speed is squared in the kinetic energy equation?
A hammer and a feather are dropped at the same time on the Moon. Which hits the ground first?
What is they hit the ground at the same time because there is no air resistance?
When you start to run, what types of energy are being transferred and how?
friction should not be accounted for in this question.
The types of energy present are chemical energy and kinetic energy.
The chemical energy is being transferred into kinetic energy when you run.
A student defines the system in a ramp lab as “the cart only.” Why might this system definition make it harder to explain energy changes?
What is energy transfers to the ramp, track, or surroundings would not be included in the system?
How does friction affect mechanical energy?
Friction in a system causes mechanical energy to be converted into thermal and acoustic energy.
A heavier object and a lighter object slide down the same ramp without friction. Which reaches the bottom with greater speed?
What is they reach the bottom with the same speed?
You push a wall with all your strength, but it doesn’t move. According to Newton’s Third Law, what force acts on you?
What is the wall pushes back on you with an equal and opposite force?
Using the formula solve the following problem GPE=mgh and KE=1/2mv²
If a ball is on a ramp and at the top of the ramp the height is 9.144m and the ball has a mass of 0.02kg and when the ball drops it is moving at 15 m/s and the ramp is frictionless and gravity = 9.8 m/s²
When is the total energy at the top of the ramp and how does the energy change as the ball rolls down the ramp?
At the top of the ramp the ball has a total energy of 1.79J and as the ball rolls down the ramp that energy is transferred to KE.
( The formula for KE being there is just to make you overthink the total energy, testing if you know that energy stays constant. XD.)
An energy bar chart shows total energy decreasing as a cart moves down a ramp. What mistake might the model contain?
What is energy leaving the system was not accounted for (like thermal energy)?
Suppose there is a 15kg SLEEPY DOG at the top of a 2m ramp. It somehow rolls down. How much GPE does it have at the start, where does the energy go, and what form does it become?
At the start, the 15 kg dog has 294.3 J of Gravitational Potential Energy (GPE). As it rolls down the ramp, this energy is converted into other forms to satisfy the principle of conservation of energy (thermal)
Why is it important to define the system when analyzing energy changes?
What is so we know where energy starts, ends, and transfers?
A bowling ball and a tennis ball are dropped from the same height in a vacuum. Which has greater acceleration due to gravity?
What is they have the same acceleration due to gravity?
A toy car is 40 grams and moves at 2 meters per second
What is the toy car’s kinetic energy?
(mass must be in kg)
The kinetic energy of the toy car is 0.08 Joules.
If Jesse (60 kg) is standing on top of a 100- meter cliff, how much gravitational potential energy would they have?
60 * 9.8 * 100 = 58,800 Joules
Explain why energy conservation still applies even when energy appears to “disappear” during motion.
What is energy was transferred to forms like thermal energy that may not be easily observed?
In real-world systems, why is kinetic energy at the bottom of a ramp often slightly less than the potential energy at the top?
What is energy transfers to thermal energy through friction?
A car moving at 60 mph suddenly brakes and skids to a stop. Which physical concept explains why the car keeps moving forward before stopping?
What is inertia (Newton’s First Law of Motion)?