Skip to content

Course home

Sign up

8 Energy – forces doing work

EasyMediumHard
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110
Question 41
F

A student measures her useful power output by running up a flight of stairs.

The Figure shows the stairs.

Figure

image

The mass of the student is 54 kg.

She takes 4.5 s to run from the start to the finish.

Gravitational field strength (ggg) = 10 N/kg

a.

Calculate the increase in gravitational potential energy of the student.

[2]
b.

Calculate the useful power output of the student.

[2]
c.

A second student has a mass of 72 kg. He takes 6.0 s to run up the same stairs.

He says:

'My power output is greater than hers because I do more work.'

Explain whether he is correct.

[3]
d.

The time is measured with a stopwatch.

Suggest one reason why the value of the power calculated may not be accurate.

[1]
Markscheme

8 Energy – forces doing work Questions

  1. GCSE
  2. /Physics
  3. /8 Energy – forces doing work

Question bank