# Question #ee3f1

Jan 28, 2018

The potential energy is $= 150 J$

#### Explanation:

To calculate the potential energy, calculate the height after $2 s$

Apply the equation of motion

Resolving in the direction ${\uparrow}^{+}$

$h = u t - \frac{1}{2} g {t}^{2}$

The initial velocity is $u = 15 m {s}^{-} 1$

The acceleration due to gravity is $g = 10 m {s}^{-} 2$

The time is $t = 2 s$

The height is

$h = 15 \cdot 2 - \frac{1}{2} \cdot 10 \cdot {2}^{2} = 30 - 20 = 10 m$

The mass is $m = 1.5 k g$

The potential energy is

$P E = m g h = 1.5 \cdot 10 \cdot 10 = 150 J$