A block of mass 2kg is thrown in upward direction with speed 20 m/s and height gain by the particle is 15 m. Find work done by air resistance is–700 J700 J100 J–100 J

To find the work done by air resistance, we can use the equation:

Work = Force x Distance

First, let's calculate the force of air resistance. Air resistance is a type of frictional force that opposes the motion of the block. It can be calculated using the equation:

Force of air resistance = 0.5 * coefficient of air resistance * density of air * velocity^2 * area

However, since we are not given the coefficient of air resistance, density of air, or the area of the block, we cannot calculate the force of air resistance directly.

Instead, we can use the work-energy principle. According to this principle, the work done by all forces acting on an object is equal to the change in its kinetic energy.

The initial kinetic energy of the block can be calculated using the equation:

Initial kinetic energy = 0.5 * mass * velocity^2

The final kinetic energy of the block can be calculated using the equation:

Final kinetic energy = 0.5 * mass * final velocity^2

Since the block reaches its highest point and comes to rest, the final velocity is 0 m/s.

Therefore, the change in kinetic energy is:

Change in kinetic energy = Final kinetic energy - Initial kinetic energy = 0 - (0.5 * mass * velocity^2)

Now, we can calculate the work done by air resistance using the equation:

Work = - Change in kinetic energy

Substituting the given values:

Work = - (0.5 * 2 kg * (20 m/s)^2) = - (0.5 * 2 kg * 400 m^2/s^2) = - (400 J) = - 400 J

Therefore, the work done by air resistance is -400 J.