11th grade Energy accounting in open, closed and isolated systems worksheet

Energy accounting in open, closed and isolated systems

Grade 11 Science Worksheet - Building Confidence

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

1. 1.

   A motor does 500 J of work on a cart-and-track system, while 320 J of heat leaves it into the room. By how much does the system's energy grow, Bo?
2. 2.

   A motor does 1200 J of work on a cart-and-track system, while 750 J of heat leaves it into the room. By how much does the system's energy grow, Esme?

3. Read this first

   Use this

   Energy bar chart (example data), one bar per energy store, height in J. Before: kinetic 0 J; thermal 0 J. After: kinetic 150 J; thermal 50 J. A transfer arrow goes from the motor to the cart and track, labeled work 200 J. A dashed system boundary surrounds the cart and the track. The motor is outside it; its work arrow crosses the boundary inward.

4. 3.

   In the energy bar chart, how much energy crosses the system boundary, Jun?

   • 150 J
   • 50 J
   • 200 J
5. 4.

   In the energy bar chart, how much of the motor's work ends up as thermal energy, Kira?

   • 150 J
   • 200 J, the whole amount
   • 50 J
6. 5.

   In the energy bar chart, why do the system's stores grow, Luz?

   • Work from the motor crosses into the system
   • Energy is made inside the system
   • The track adds extra energy to the cart
7. 6.

   A pot of soup simmers on a stove with no lid. Steam escapes and heat flows in. What kind of system is the soup, Milo?

   • Closed: energy crosses but matter does not
   • Open: matter and energy cross
   • Isolated: nothing crosses
8. 7.

   A sealed jar of water warms in the sun. What kind of system is the water in the jar, Noah?

   • Open: matter and energy cross
   • Closed: energy crosses but matter does not
   • Isolated: nothing crosses
9. 8.

   A box slides to a stop on a rough floor. Where did its kinetic energy go, Ren?

   • Into thermal energy in the box and floor
   • It was destroyed
   • Into gravitational energy
10. 9.

    A cart rolls to a stop on a carpet. What happened to the total energy of the cart, carpet and air, Tala?

    • It was used up
    • It grew, since the carpet warmed
    • It stayed the same
11. 10.

    A cart's brake pads squeal and warm as it slows. Which stores gain energy, Zee?

    • Thermal energy and sound
    • Kinetic energy
    • Gravitational energy, since it slows