Answer:
power = 32.09 watt
work done = 28854 J
Step-by-step explanation:
a) mass of subject = 60 kg speed = 3.5 mph = 5.63 kph = 1.564 m/s
grade = 3.5% time= 15 min
tan θ = 0.035
θ = 2°
power = F × v
= mg sin θ × v cos Φ
= 60 × 9.8 × sin2° × 1.564 × cos 180°
= -32.09 watt
work done = power × time
= 28854 J
b) in this part work done is equal to zero.
because the angle between the motion of subject and the force acting is 90° hence cos 90° equals to zero so, work done equal to zero.