Question

A parachutist reaches terminal speed when:

a) weight goes to 0
b) the force of air resistance equals her weight
c) the force of air resistance exceeds her weight
d) the force of air resistance equals her mass
Two steel balls haev the same size and shape, but one ishollow. They are dropped in the air and their terminal speed ismeasured. Which of the following statements is correct?
a) the hollow ball has a smaller tenimal speed because itrequires a smaller air resistance to cancel the gravitational forceon it
b) the hollow ball has a larger terminal speed because itrequires a smaller air resistance to cancel the gravitational forceon it.
c) the terminal speeds are the same and equal to 10 m/s
d) the teminal speeds are the same because the accelertaion ofgravity doesnt depend on mass.
please help me.

Answer 1

A parachutist reaches terminal speed when the force of air resistance equals her weight. The hollow steel ball has a smaller terminal speed, and an object on zero-friction ice keeps moving at constant speed when the applied force stops.

Step-by-step explanation:

A parachutist reaches terminal speed when the force of air resistance equals her weight, which is answer (b) to the first question. Regarding the two steel balls dropped in the air, the correct statement is (a) the hollow ball has a smaller terminal speed because it requires a smaller air resistance force to balance the gravitational force on it.When a force is applied to an object on a smooth icy surface with zero friction, and the force stops, the object's acceleration becomes zero while its speed remains constant. Thus, the correct answer is (a). If a parachutist is falling with a gravitational force of 539 N acting on her and then opens her parachute to experience an air resistance of 615 N, she is falling at a terminal velocity, meaning the acceleration is zero, and speed remains constant.For an 80.0-kg skydiver falling headfirst with a surface area of 0.140 m², we can calculate the terminal velocity using the drag force equation that sets the drag force equal to the weight of the skydiver when terminal velocity is reached.