A 5.00 kg box is on a ramp that is inclined at [tex]$21.0^{\circ}$[/tex].

What is the [tex]$y$[/tex]-component of the weight of the box?

[tex] w_y = [?] \, \text{N} [/tex]



Answer :

To find the [tex]$y$[/tex]-component of the weight of the box, we'll follow these steps:

1. Determine the weight of the box.

The weight [tex]$W$[/tex] of the box is given by the formula:
[tex]\[ W = m \times g \][/tex]
where:
- [tex]\(m\)[/tex] is the mass of the box,
- [tex]\(g\)[/tex] is the acceleration due to gravity.

Given:
[tex]\[ m = 5.00 \text{ kg} \][/tex]
[tex]\[ g = 9.81 \text{ m/s}^2 \][/tex]

Thus, the weight [tex]\(W\)[/tex] is:
[tex]\[ W = 5.00 \text{ kg} \times 9.81 \text{ m/s}^2 = 49.05 \text{ N} \][/tex]

2. Resolve the weight into the [tex]$y$[/tex]-component.

The [tex]$y$[/tex]-component of the weight, denoted as [tex]\( w_y \)[/tex], is the component of the weight that acts perpendicular to the plane of the ramp.

Using trigonometry, the [tex]$y$[/tex]-component can be found using the cosine of the angle of inclination:
[tex]\[ w_y = W \times \cos(\theta) \][/tex]
where:
- [tex]\( \theta \)[/tex] is the angle of the incline,
- [tex]\( W \)[/tex] is the weight of the box.

Given:
[tex]\[ \theta = 21.0^\circ \][/tex]

Thus, the [tex]$y$[/tex]-component of the weight is:
[tex]\[ w_y = 49.05 \text{ N} \times \cos(21.0^\circ) \][/tex]

3. Substitute the known values and calculate.

Using the cosine of [tex]\( 21.0^\circ \)[/tex]:
[tex]\[ \cos(21.0^\circ) \approx 0.93358 \][/tex]

Therefore:
[tex]\[ w_y = 49.05 \text{ N} \times 0.93358 \approx 45.79 \text{ N} \][/tex]

Thus, the [tex]$y$[/tex]-component of the weight of the box is approximately:
[tex]\[ w_y \approx 45.79 \text{ N} \][/tex]
So, the [tex]$y$[/tex]-component of the weight of the box is [tex]\( \boxed{45.79 \text{ N}} \)[/tex].