Question

A skier of mass 70 kg is pulled up a slope by a motor-driven cable. The acceleration of gravity is 9.8 m/s 2 . How much work is required to pull him 62.5 m up a 38.4 ◦ slope (assumed to be frictionless) at a constant speed of 3.77 m/s.

Answer 1

Answer:26.65 kJ

Explanation:

Given

mass of skier=70 kg

length of ramp=62.5 m

slope$=38.4 ^{\circ}$

speed=3.77 m/s

so net force on skier must be zero

Net work done will be change in Potential energy of skier

Potential Energy$=mg(\Delta H)$

$\Delta H=62.5sin38.4=38.821 m$

$P.E.=70\times 9.81\times 38.82=26,658.88 J$

P.E.=26.65 kJ