Question

$3.0m{s}^{-2}=$___ $km{h}^{-2}$

• A. $3.9\times 10^4$
• B. $3.9\times 10^2$
• C. $390$
• D. $3.9$

Answer 1

Answer: (A)

$3m{s}^{-2}=3m{s}^{-2}\times \left[\frac{1km}{1000m}\right]\times {\left[\frac{3600s}{1h}\right]}^2$
$\Rightarrow 3m{s}^{-2}=\left(\frac{3\times 3600\times 3600}{1000}\right)km{h}^{-2}$
$=38880km{h}^{-2}$
$\Rightarrow 3m{s}^{-2}\approx 3.9\times 10^{4}km{h}^{-2}$