Energy Transformations
When a volleyball player slides across the court and stops, where does most of the kinetic energy go?
What is heat/thermal energy/friction
What two things must be parallel to each other in order for work to be done?
A roller coaster starts from rest at the top of a 10 m hill. Ignoring friction, what type of energy is greatest at the bottom
What is kinetic energy.
The work done by friction results in a transformation of this type of energy into this other type of energy.
What is mechanical energy into thermal energy.
This term refers to the average kinetic energy of the molecules in an object.
What is temperature.
This type of energy is stored in an object.
What is potential energy.
A Ms.Mark pushes a crate with 50 N of force over 8.0 m. How much work does she do on the crate?
What is 400 J.
A 3.0 kg object falls from a height of 8.0 m. What is its speed just before hitting the ground? Ignore air resistance.
What is 12.5 m/s
A puddle and a lake are both 20°C. Which has more thermal energy?
What is the lake.
This type of energy is the sum of an objects kinetic and potential energies.
What is Mechanical Energy.
A 2.0 kg backpack is lifted 5.0 m into a tree. How much gravitational potential energy does it gain?
What is 98 J.
Applied force, friction, air resistance, and drag are all examples of this kind of work.
What is non-conservative.
A cart has 500 J of mechanical energy at the top of a track. If 120 J is lost to friction, how much mechanical energy remains?
What is 380 J.
A 10 kg glider starts from rest at height 5.0 m and lands. Friction removes 500 J of energy. If c=600, what is ΔT?
What is 0.083 K (or degrees Celsius).
WNC+EK+EP=W'NC+E'K+E'P combines these two energy theorems.
What are Conservation of Mechanical Energy and the Work Energy theorem.
A 0.50 kg arrow leaves a bow at 20 m/s. What is its kinetic energy?
What is 100 J.
An airplane engine does 12 000 J of work in 4.0 s. What is its power output?
What is 3000 W.
A 1200 kg car moving at 18 m/s brakes to a stop. How much kinetic energy is lost?
What is 1.9x105 J.
If 50 000 J of heat is removed from 4.0 kg of water, what is the temperature decrease?
What is 3 K (or degrees celsius)
When an object is lifted vertically at a constant velocity, work is done against this entity.
What is gravity.
How much heat must be transferred into 5.0 kg of water to raise its temperature from 20 to 97 degrees celsius if c=4184 J/kgK?
What is 1.6x10^6 J.
A 65 kg student climbs a rope 6.0 m in 3.0 s. What is their power output?
What is 1.3x103 W.
A roller coaster is at the top of a 20 m hill with an initial speed of 10 m/s. What is the speed at the bottom of the hill (assuming no losses)?
What is 22.2 m/s.
A 0.65 kg puck is sliding along a horizontal surface at a speed of 2.0 m/s. If the puck comes to a stop in 5.5 m, what is the force of friction acting along the surface?
What is 0.24 N.
What quantity can also be expressed as joules per second?
What is power.