Unit 2
4 marks · EasyA physicist records a measurement in standard form as metres. She then substitutes this distance into the equation , where m/s and is the time in seconds.
Write metres as an ordinary number.
Work out the value of , giving your answer in standard form.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
(a) 68,000,000 metres
(b) 3.4 \times 10^4 seconds
Common mistakes: Incorrect placement of decimal point when converting to ordinary number; Arithmetic errors multiplying/dividing standard form
Show mark scheme and worked solution
Marking points
B1 (a) · 1 mark · Correctly writes 6.8 \times 10^7 as 68,000,000
M1 (b) · 1 mark · Divides by or shows clear method for substitution
M2 (b) · 1 mark · Uses rules for dividing numbers in standard form correctly
A1 (b) · 1 mark · Gives final answer as seconds in standard form (follow-through)
Worked solution
(a) metres.
(b) Substitute into : .
So seconds.