Question

A students lab group has already agreed on the following two ideas:

1) When an object is at terminal velocity, the kinetic energy is constant.

2. The decrease in gravitational energy over a given distance is proportional to the number of filters.

Which of the additional ideas below would most be helpful in deciding how the increase in thermal energy depends on the number of coffee filters?

a) When an object is at terminal velocity, the increase in thermal energy compensates for the decrease in gravitational energy.

b) The increase in thermal energy is proportional to the change in temperature of an object.

c) The kinetic energy of an object is proportional to the speed of the object squares.

d) When an object is at terminal velocity, the drag force is equal to the gravitational force.

Answer 1

As speed increases, the drag force increases, and so does the rate of energy transfer to the air. It means gravitation potential energy is converting to kinetic energy and kinetic energy is transferred to thermal energy.

so,

When an object is at terminal velocity, the increase in thermal energy compensates for the decrease in gravitational energy.