Question

A child holds onto a string attached to a toy boat and exerts a force of 7.5 N to pull the boat a distance of 9.2 m a long a straight shoreline. If the child holds the string at the 15 angle with the horizontal, how much work does the child do in the toy boat

Answer 1

The work that need to do is 66.24 J.

Explanation :

Hello guys, before we can count how much the work that needed to pull the toy, we should know how formula to count it first. Because the movement is with the angle, so the formula is :

$\boxed {\bold {W = F \times s \times \cos(\theta)}}$

If :

• W = work (J)
• F = force (N)
• s = shift (m)
• θ = elevation angle (°)

We know that :

• x = the horizontal shift = 9,2 m
• θ = elevation angle = 15°

W = work = ... J

$W = F \times s \times \cos(\theta) \\ W = 7.5 \times 9.2 \times \cos(15) \\ W = 69 \times 0.96 = 66.24 \: J$

So, the work that need to do is 66.24 J.

Subject : Physics

Class : Junior High School/Senior High School

Keyword : Work; Force; Shift; and Elevation Angle