Questions: A 17. An 72 kg man is lifted by a helicopter 15 m vertically by a cable. a=9 / 10. How much work is done by: a) The force from the helicopter?

Solution Steps

The force exerted by the helicopter is equal to the gravitational force acting on the man, which is his weight. The weight \( W \) can be calculated using the formula:

\[ W = m \cdot g \]

where \( m = 72 \, \text{kg} \) is the mass of the man and \( g = 9.81 \, \text{m/s}^2 \) is the acceleration due to gravity.

Substitute the given values into the formula:

\[ W = 72 \, \text{kg} \times 9.81 \, \text{m/s}^2 = 706.32 \, \text{N} \]

The work done by the force from the helicopter is given by the formula:

\[ \text{Work} = F \cdot d \cdot \cos(\theta) \]

where \( F = 706.32 \, \text{N} \) is the force, \( d = 15 \, \text{m} \) is the distance, and \( \theta = 0^\circ \) because the force and displacement are in the same direction.

Since \(\cos(0^\circ) = 1\), the work done is:

\[ \text{Work} = 706.32 \, \text{N} \times 15 \, \text{m} \times 1 = 10594.8 \, \text{J} \]

Final Answer