Question

Please help me with this standard form question!
6.The speed of light is approximately 3 x 10^8 metres per second. How far will light travel in:
a) 10 seconds b) 20 seconds c) 102 seconds.
I tried multiplying by ten for the first one and then I ran out of ideas.

Answer 1

Yes

distance = speed*time

Answer 2

you just need to multiply

Answer 3

for a,

distance = 3 x 10^8 m/s * 10 s = 3 x 10^9 m

Answer 4

see if you can try b

Answer 5

You can convert the seconds into standard form: x * 10^y

10 = 1 * 10^1

20 = 2 *10^1

102 = 1.02 *10^2

When multiplying, multiply 3 by "x" and 10^8 by y.

3*x = 3x

10^8 * 10^y = 10^8+y

Can you solve them now?

Answer 6

Actually, still not a hundred percent. When multiplying wouldnt it be 30 x 10^18 ? Can you please explain why you dont multiply the three and why the exponent only increased by one?

Answer 7

d = 3 x 10^8 m/s x 10 s
= 3 x 10^8 x 10 m
= 3 x 10^8 x 10^1 m
= 3 x 10^{8+1} m
= 3 x 10^9 m

Answer 8

Thank you. :)