Write the following quantities in standard form.

Question

Write the following quantities in standard form.

(a) 6400 km (b) 38000 km
(c) $300000000 ms^{-1}$ (d) seconds in a day
{(a) $6.4 imes10^{3} km$ (b) $3.8 imes 10^{5}$ km (c) $3 imes10^{8} ms^{-1}$ (d) $0.64 imes10^{4s}$

Accepted Answer

Solution:

(a) 64000 km

Multiplying and dividing by “$10^{3}$”

=6400 $\frac{m}{1000} imes 10^{3}$km

=$64 \frac{m}{10} imes 10^{3}$km

=$6.4 imes10^{3}$ km

(b) 38000 km

Multiplying and dividing by “$10^{5}”$

=$\frac{38000}{10^{5}} imes10^{5}km$

=$\frac{380000}{380000} imes 10^{5}km$

= $3.8 imes 10^{5}$ km

(c) 300000000 $ms^{-1}$

Multiplying and dividing by “$10^{8}$”

$\frac{300000000 ms^{-1}}{100000000} imes10^{8}km$

= $3 imes 10^{8}$ km

(d) seconds in a day

As we know

1 day =24 hours

1 hour= 60 minutes

1 minute = 60 seconds so

1 day = $24 imes 60 imes 60$ seconds

1 day = 86400 s

Multiplying and dividing by $10^{4}$

=$\frac{86400}{10000} imes10^{4} s$

=$8.4 imes10^{4} s$