Weight, mass and the normal force

Answer Key - Grade 11 Science Worksheet - Challenge Me

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

1. 1.

   A 5 kg box on a scale in an elevator reads 54 N. With g = 9.8 m/s² and up positive, what is the elevator's acceleration, Ari?

   1 m/s²
2. 2.

   A 2 kg box on a scale in an elevator reads 25.6 N. With g = 9.8 m/s² and up positive, what is the elevator's acceleration, Esme?

   3 m/s²

3. Read this first

   Scale readings for a 5 kg box during an elevator ride (example data)

   part of the ride	scale reading (N)
   starting upward	59
   rising at a steady speed	49
   slowing near the top	44

4. 3.

   In the ride table, what is the acceleration while starting upward, Jun?

   • 2 m/s² upward
   • 2 m/s² downward
   • 0 m/s²
   • 11.8 m/s² upward
5. 4.

   In the ride table, what is the acceleration while slowing near the top, Kira?

   • 8.8 m/s² upward
   • 0 m/s²
   • 1 m/s² downward
   • 1 m/s² upward
6. 5.

   In the ride table, during which part is the elevator not accelerating, Luz?

   • Slowing near the top
   • Rising at a steady speed
   • The starting and slowing parts
   • Starting upward
7. 6.

   Noah says a scale in an elevator reads more whenever the elevator is moving up. Agree or disagree?

   • Agree: the box gains mass going up
   • Disagree: only upward acceleration raises it
   • Agree: moving up adds to the reading
   • Agree: normal force is always the weight
8. 7.

   Pia says the normal force on a box can differ from its weight. Agree or disagree?

   • Disagree: motion is what changes it
   • Disagree: a surface pushes back with the full weight
   • Agree: on a ramp it is mg cos θ
   • Disagree: mass and weight are the same thing
9. 8.

   A drone lifts a 3 kg box, accelerating it upward at 1 m/s². With g = 9.8 m/s², what is the cable's pull, Ren?

   • 29.4 N
   • 3 N
   • 26.4 N
   • 32.4 N
10. 9.

    A 2 kg mass hangs from a spring scale in an elevator accelerating downward at 1.8 m/s². What does the scale read, Tala?

    • 19.6 N
    • 16 N
    • 1.8 N
    • 23.2 N
11. 10.

    A spring scale and a balance both measure a 1 kg mass on the Moon. Which one shows a different result than on Earth, Zee?

    • The balance, which compares masses
    • Both change the same way
    • Neither changes
    • The spring scale, which measures weight