Energy changes in a system, and the ways energy is stored before and after such changes

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Question 16
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An experiment is performed to determine a student's power output by running to the top of a flight of stairs.

A student running up a flight of stairs. The starting position is at the bottom of the stairs, and the ending position is at the top platform. The vertical distance between the ground floor and the top platform is labeled 'Height'.

a.
  • The mass of the student, Sarah, is 54.0 kg54.0\text{ kg}54.0 kg.
  • The height of the stairs is 200 cm200\text{ cm}200 cm.
  • Sarah ran to the top of the stairs in 1.20 s1.20\text{ s}1.20 s.
  • The gravitational field strength is g=9.8 N/kgg = 9.8\text{ N/kg}g=9.8 N/kg.

Calculate the useful power output of Sarah.

[3]
b.

The total power output of Sarah was actually greater than the value calculated in Part 1. Suggest two reasons why.

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c.

Another student, James, took less than 1.20 s1.20\text{ s}1.20 s to run up the same stairs. The power output of James was measured to be the same as the power output of Sarah.

What conclusion can be made about James's mass?

  • James's mass was greater than Sarah's mass.
  • James's mass was lower than Sarah's mass.
  • James's mass was the same as Sarah's mass.
[2]

Energy changes in a system, and the ways energy is stored before and after such changes Questions

  1. GCSE
  2. /Physics
  3. /Energy changes in a system, and the ways energy is stored before and after such changes