Units Scalar/Vector
The property vectors have that scalars don't is ___
Direction
What is the unit for power?
Watts
What is the only force ever acting on a projectile in air?
Gravity
What do physicists equate the weight of 1 Newton to?
An apple
Is momentum a scalar or vector?
Vector
The difference between distance and displacement is ___
Distance: Total distance traveled
Displacement: How far from start to finish
What is work?
Force applied through a distance (F x D)
What launch angle will keep an object in air the longest?
90o
What is Newton's 1st Law?
An object in motion will stay in motion unless acted on by another force
What is the general equation for momentum?
p = mv
Instantaneous velocity is ___
Velocity at a certain moment in time
What is the equation for power?
(Force x Distance) / Time
What launch angle will result in the furthest horizontal distance?
45o
What equation is used for Newton's 2nd Law?
Fnet = ma OR a = Fnet / m
What is impulse?
The change in momentum during a collision
How many forces act on an object in freefall and which ones?
1 force - Gravity
A motor converts electrical energy into ___
Kinetic Energy
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
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
A 10kg object moving at 5m/s collides with a 15kg object at rest. How fast is the system moving after colliding?
2m/s (pi=pf) --> (50 = 25(vf))
What is the term for when all forces on an object add to zero, but the object is moving at constant speed?
Dynamic Equilibrium
What is an ideal energy system?
A (non-existent) system with no friction, heat loss, permanent deformation, or sound, while conserving all mechanical energy.
What equation can you use to figure out the initial horizontal velocity of a projectile?
A (costheta)
The force that acts opposite to the weight of an object on a surface is ___
Normal Force
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.