P3g: Falling safely

Question 1

Explain how objects falling through the Earth’s atmosphere reach a terminal speed(3)

Answer 1

When an object falls, it accelerates. As its speed increases, the air resistance increases, so the drag increases

Eventually, the force from the air resistance will equal the force from the weight of the object, so weight equals drag

At that point, the speed will remain constant: the object has reached its “terminal velocity” and can’t fall any faster.

Question 2

How can you increase drag(2)

Answer 2

higher speed = more drag

larger area = more drag

Question 3

Describe what happens with a falling object with no atmosphere

Answer 3

There is no drag on falling objects when there is no atmosphere. This means that the acceleration of falling objects due to gravity is the same whatever their mass and shape.

Question 4

Describe gravitational field strength or acceleration due to gravity(3)

Answer 4

unaffected by atmospheric changes

varies slightly at different points on the Earth’s surface
-will be slightly different on the top of a mountain or down a mineshaft