Energy accounting in open, closed and isolated systems

Grade 11 Science Worksheet - Challenge Me

NameDate

Circle the best answer, or write your answer on the line.

A motor does 500 J of work on a cart-and-ramp system. The cart gains 294 J of gravitational and 120 J of kinetic energy. How much thermal energy is made, Ari?
A motor does 800 J of work on a cart-and-ramp system. The cart gains 392 J of gravitational and 250 J of kinetic energy. How much thermal energy is made, Esme?
3.
An electric kettle with no lid takes in 300 kJ. The water gains 250 kJ of thermal energy and 30 kJ leaves with the steam. Where are the other 20 kJ, Jun?
- Destroyed in the heater
- Stored as gravitational energy in the steam
- Warming the kettle and the room air
4.
Why is a kettle with no lid an open system, Kira?
- No energy can cross its boundary
- Its water stays inside the kettle
- Steam, which is matter, leaves it
5.
What change would make a lidless kettle a closed system, Luz?
- A tight lid, so no steam escapes
- Thick insulation, with the top still open
- A bigger heater
6.
Milo says friction destroys energy when a box slides to a stop. Agree or disagree?
- Disagree: it becomes thermal energy
- Agree: the kinetic energy is gone for good
- Agree: the box ends with less energy, so energy was lost from the world
7.
Pia says a closed system's total energy can change. Agree or disagree?
- Agree: energy can cross its boundary
- Disagree: closed means nothing crosses
- Disagree: its matter stays the same, so its energy does too
8.
A drone's battery gives out 900 J while it lifts a 2 kg box 30 m at a steady speed. With g = 9.8 m/s², how much goes to heat and moving air, Ren?
- 312 J
- 588 J
- 1488 J
9.
A spring launcher stores 12 J. The ball it launches leaves with 9 J of kinetic energy. Where did the other 3 J go, Tala?
- Thermal energy and sound in the launcher
- Back into the spring
- Into the ball's mass
10.
A 1 kg cart starts at rest, drops 2 m down a ramp and reaches 6 m/s. With g = 9.8 m/s², how much thermal energy did friction make, Zee?
- 37.6 J
- 18 J
- 19.6 J
- 1.6 J

Energy accounting in open, closed and isolated systems

Answer Key - Grade 11 Science Worksheet - Challenge Me

Circle the best answer, or write your answer on the line.

A motor does 500 J of work on a cart-and-ramp system. The cart gains 294 J of gravitational and 120 J of kinetic energy. How much thermal energy is made, Ari?
86 J
A motor does 800 J of work on a cart-and-ramp system. The cart gains 392 J of gravitational and 250 J of kinetic energy. How much thermal energy is made, Esme?
158 J
3.
An electric kettle with no lid takes in 300 kJ. The water gains 250 kJ of thermal energy and 30 kJ leaves with the steam. Where are the other 20 kJ, Jun?
- Destroyed in the heater
- Stored as gravitational energy in the steam
- Warming the kettle and the room air
4.
Why is a kettle with no lid an open system, Kira?
- No energy can cross its boundary
- Its water stays inside the kettle
- Steam, which is matter, leaves it
5.
What change would make a lidless kettle a closed system, Luz?
- A tight lid, so no steam escapes
- Thick insulation, with the top still open
- A bigger heater
6.
Milo says friction destroys energy when a box slides to a stop. Agree or disagree?
- Disagree: it becomes thermal energy
- Agree: the kinetic energy is gone for good
- Agree: the box ends with less energy, so energy was lost from the world
7.
Pia says a closed system's total energy can change. Agree or disagree?
- Agree: energy can cross its boundary
- Disagree: closed means nothing crosses
- Disagree: its matter stays the same, so its energy does too
8.
A drone's battery gives out 900 J while it lifts a 2 kg box 30 m at a steady speed. With g = 9.8 m/s², how much goes to heat and moving air, Ren?
- 312 J
- 588 J
- 1488 J
9.
A spring launcher stores 12 J. The ball it launches leaves with 9 J of kinetic energy. Where did the other 3 J go, Tala?
- Thermal energy and sound in the launcher
- Back into the spring
- Into the ball's mass
10.
A 1 kg cart starts at rest, drops 2 m down a ramp and reaches 6 m/s. With g = 9.8 m/s², how much thermal energy did friction make, Zee?
- 37.6 J
- 18 J
- 19.6 J
- 1.6 J