SP1d Newton's first and second laws

Question 1

Newton’s first law?

Answer 1

an object will remain stationary or at constant speed unless acted on by an external force.

Question 2

Newton’s second law?

Answer 2

an object will accelerate when an outside resultant force is applied to the object.

Question 3

What does acceleration in the direction of a resultant force depend on? (2)

Answer 3

.the size of the resultant force (the difference between the 2 or more forces)
.the mass of the object

Question 4

Centripetal force?

Answer 4

causes objects to follow a circular path. The force acts towards the centre of the circle.

Question 5

Explain that an object moving in a circular orbit at a constant speed has a changing velocity.

Answer 5

Velocity is a vector; it has both direction and magnitude. Velocity is constantly changing because the direction is constantly changing.

Question 6

What is the resultant force causing acceleration?

Answer 6

centripetal force.

Question 7

What is the centripetal force of:
.car travelling around a round about
.ball attached to a rope
.earth orbiting the sun

Answer 7

:
.friction between the tyres and the road
tension on the rope
.gravitational