# Question 384a4

Jun 27, 2015

The reactive force exerted on the body will be equal to 25 N.

#### Explanation:

An equilateral triangle has all three internal angles equal to ${60}^{\circ}$.

This means that, regardless on which side your triangle stands on, its other two sides will form ${60}^{\circ}$ angles with the horizontal.

Either side of the triangle will thus be equivalent to an inclined plane

The normal force exerted on the body will be equal to

$N = m g \cdot \cos \left(\theta\right)$, where

$m$ - the mass of the body;
$g$ - the gravitational acceleration;
$\theta$ - the angle formed by the inclined plane with the horizontal.

Plug your values into the above equation and solve for $N$ (assume $g$ to be equal to $10 {\text{m/s}}^{2}$)

$N = {\text{5 kg" * 10"m"/"s}}^{2} \cdot \cos \left({60}^{\circ}\right)$

N = 50 underbrace(("kg" * "m")/"s"^2)_(color(blue)("=Newton")) * 1/2 = color(green)("25 N")#