On a snowy day, max (mass = 15 kg) pulls his little sister maya in a sled (combined mass = 20 kg) through the slippery snow. when max pulls on the sled with 12 n of force, directed at an angle of 15° above the ground, how much work does max do on the sled as he pulls his sister 25 m in the snow?

290 J

Explanation:

1) Data:

i) Max's mass = 15 kg

ii) Maya in a sled's mass = 20 kg

iii) slippery snow ⇒ no friction

iv) F = 12 N

v) α = 15°

vi) d = 25 m

2) Physical principles and formula

i) The mechanical workg, W, developed by a constant force, F, that has an angle α with the displacement d, is given by the formula:

W = F × d × cos(α).

ii) The mass of Max is not relevant for the problem, nor the mass of the sled, since the fact that there is not friction, results in that the only force acting is F (12 N, α = 12°).

3) Solution:

W = 12 N × 25m × cos (15°) ≈ 290 J

answer: 31, 5556. 952 seconds