SP2b Newtons First Law

Question 1

Describe the effect of balanced forces on moving and stationary objects.

Answer 1

The motion of an object will not change if the forces pushing or pulling the object are balanced.
. If an object is in motion, it will keep moving in the same direction and at the same speed if the forces acting on it are balanced.

Question 2

Describe circular motion at constant speed as a changing velocity and hence as an acceleration.

Answer 2

When an object moves in a circle at a constant speed, its direction constantly changes. A change in direction causes a change in velocity. This is because velocity is a vector quantity – it has an associated direction as well as a magnitude. A change in velocity results in acceleration, so an object moving in a circle is accelerating even though its speed may be constant.

Question 3

Describe the force needed to keep an object moving in a circular path.

Answer 3

For an object moving in a circle, this resultant force is the centripetal force that acts towards the middle of the circle.