Some runners train with parachutes that trail behind them to provide a large drag force. these parachutes have a large drag coefficient, by design. one model expands to a rectangle 1.8 m square, with a drag coefficient of 1.4. a runner completes a 200 m run at 5.0 m/s with this chute trailing behind. how much thermal energy is added to the air by the drag force?

To develop this problem it is necessary to apply the concepts related to the Aerodynamic Drag Force.

By definition the Drag Force is defined as

Where,

A = Area

= Density

= Drag coefficient

v = Velocity

According to our values we have,

Replacing we have

By definition we know that the thermal energy is given by the force applied in a given displacement then

Therefore the thermal energy is added to the air by the drag force is 13.9kJ

yup its correct its: c) b b

the chart show the masses and velocities of two colliding objects that stick together after a collision.

according to the law of conservation of momentum, the momentum of the object after the collision is  

answer

1,500

kg • m/s.