# How do you find the angle in this question?

## A man drags a package across the floor with a force of 40 N directed at an angle (unknown) to the horizontal. The mass of the package is 10 kg. If the acceleration of the package is 3.5 metres per second squared, and friction is ignored, what is the unknown angle?

Mar 23, 2016

${28.9}^{\circ}$

You can find it like this:

#### Explanation:

Here's the scenario:

The horizontal component of the force applied is $40 \cos \theta$.

Newton's 2nd Law tells us:

$F = m a$

We know:

$m = 10 \text{kg}$

$a = 3.5 {\text{m/s}}^{2}$

So we can write:

$40 \cos \theta = 10 \times 3.5$

$\therefore \cos \theta = \frac{10 \times 3.5}{40} = 0.875$

From which:

$\theta = {28.9}^{\circ}$