Physics Review

Units Scalar/Vector

100

The property vectors have that scalars don't is ___

Direction

200

The difference between distance and displacement is ___

Distance: Total distance traveled

Displacement: How far from start to finish

300

Instantaneous velocity is ___

Velocity at a certain moment in time

400

How many forces act on an object in freefall and which ones?

1 force - Gravity

500

What is the term for when all forces on an object add to zero, but the object is moving at constant speed?

Dynamic Equilibrium

Work Energy Power

100

What is the unit for power?

Watts

200

What is work?

Force applied through a distance (F x D)

300

What is the equation for power?

(Force x Distance) / Time

400

A motor converts electrical energy into ___

Kinetic Energy

500

What is an ideal energy system?

A (non-existent) system with no friction, heat loss, permanent deformation, or sound, while conserving all mechanical energy.

Projectiles

100

What is the only force ever acting on a projectile in air?

Gravity

200

What launch angle will keep an object in air the longest?

90^o

300

What launch angle will result in the furthest horizontal distance?

45^o

400

Two horizontal projectiles are launched from the same height. Object A at 10m/s and Object B at 20m/s. Which object will hit the ground first?

They hit the ground at the same time

500

What equation can you use to figure out the initial horizontal velocity of a projectile?

A (cos_theta)

Newton's Law

100

What do physicists equate the weight of 1 Newton to?

An apple

200

What is Newton's 1st Law?

An object in motion will stay in motion unless acted on by another force

300

What equation is used for Newton's 2nd Law?

F_net = ma OR a = F_net / m

400

What is Newton's 3rd Law?

If an object exerts a force on another object, it will have an equal force exerted on it by the other object

500

The force that acts opposite to the weight of an object on a surface is ___

Normal Force

Momentum & Impulse

100

Is momentum a scalar or vector?

Vector

200

What is the general equation for momentum?

p = mv

300

What is impulse?

The change in momentum during a collision

400

A 10kg object moving at 5m/s collides with a 15kg object at rest. How fast is the system moving after colliding?

2m/s  (p_i=p_f) --> (50 = 25(v_f))

500

Why does a car crash with airbags have the same impulse as one without airbags?

Without airbags, the collision time is reduced, but the force is higher. With airbags, time increases, but force is reduced. They even out.