# Physics help, I'm not sure what this question is asking?

## A particle has a mass of 1.45 g and is moving at an average velocity of 13.5 cm/s. Calculate the kinetic energy for this particle. (Be sure to look carefully at the units). __ $g \frac{c {m}^{2}}{s} ^ 2$

Feb 24, 2018

$1321 g {\left(c \frac{m}{s}\right)}^{2}$ rounding to three significant digits

$1320 g {\left(c \frac{m}{s}\right)}^{2}$

#### Explanation:

kinetic energy is $\frac{1}{2} \times m \times {v}^{2}$

The mass is 1.45 g
The velocity is 13.5 cm/s

putting these values in for mass and velocity yields

$1320 g {\left(c \frac{m}{s}\right)}^{2}$

It is possible the instructor wants the units changed to meters/s and kilograms

Feb 24, 2018

$E k = 1.321 \times {10}^{-} 5 J$

#### Explanation:

$E k = \frac{1}{2} m {v}^{2}$

Remember that the SI unit for mass is kilograms and the SI unit for velocity is metres per second.

$E k = \frac{1}{2} \cdot 0.00145 \cdot {0.135}^{2}$

$E k = 1.321 \times {10}^{-} 5 J \mathmr{and} \frac{k g \cdot {m}^{2}}{s} ^ 2$