Physics Test 2 Forces

Explain Newton’s First Law

If the resultant force acting on an object is zero, there is no acceleration.

What is newtons 2nd law?

force = mass x acceleration

What is Newton’s 3rd Law?

If object A exerts a force on object B. Then B exerts an equal and opposite force back on A.

What is a scalar quantity? (With examples)

Scalar quantities only have magnitude(size)

eg: speed, distance, mass

What is a vector quantity? (With examples)

Vector quantities have magnitude and direction.

Eg: velocity, displacement, force, acceleration

What is the equation for weight?

weight = mass x gravity

Which one of weight or mass never changes and what is its unit?

Mass kg

What is friction in terms of motion?

Friction acts against movement between two surfaces.

What is terminal velocity?

The maximum speed an object when falling through air. This happens when the air resistance (drag) balances the force of gravity.

Equation for stopping distance?

Stopping distance = thinking distance + braking distance

What is thinking and Braking distance?

Thinking: distance the car travels while the driver reacts.

Braking: Distance the car travels while slowing to a stop after the brakes are applied.

What are the factors that affect stopping distance?

Speed, Mass, Road conditions, RReaction time

What does SUVAT stand for?

Displacement

initial velocity

final velocity

acceleration

time

what is the equation for acceleration?

a = v-u/t

change in velocity divided by time

What is the equation for displacement?

s = (v+u/2)t average velocity x time