Work, Energy, & Power
A ball is at the top of a ramp with 20J of potential energy. If there are no external forces, what is her kinetic energy after rolling all the way down the ramp?
20J
This is Newton’s Inverse-Square law regarding gravity.
Gm1m2/(r^2)
When the mass attached to a spring increases, what happens to its period if it is oscillating consistently?
Period increases
The relationship between force and torque (when not on an angle)
Direct
Acceleration is inversely proportional to this quantity
Mass
This is the formula for kinetic energy
KE=1/2mv^2
A cart on a roller coaster is at the top of an upside down loop. What direction is the velocity in and what direction is the acceleration in, assuming the cart was moving right leading up to the loop?
Velocity is moving left and acceleration is down, towards the middle of the loop
Do longitudinal waves move parallel or perpendicular?
Parallel
Negative direction of motion for torque
Clockwise
An object will ______ in the direction that you push it
Accelerate
What does the law of conservation of energy state?
Energy cannot be created or destroyed only converted from one form of energy to another
A car is going around a track with a radius of 200m and has a velocity of 80 m/s. Determine the angular velocity and acceleration of the car.
angular velocity=0.4 rad/s
The acceleration is zero (the velocity is constant).
What is a single disturbance that moves from point to point through a medium?
Pulse
In a system with external forces acting on it, what happens to momentum in a collision?
It does not stay constant/ loses momentum
True or False: An object is attached to a dangling mass by string and pulley. The acceleration of the system will always be in the direction the bigger mass moves in.
False
This is how you calculate power
Dividing the work done over the change in time.
An object is rotating at 20 rpm and has an angular acceleration of 0.2 rad/(s^2). The object eventually comes to rest. What is the initial angular velocity and how long is it rotating for?
Initial angular velocity=2.1 rad/s and t=10.5s
What is the main factor which affects the speed of a sound wave?
Properties of the medium
What is the resistance to rotation called?
Rotational inertia or moment of inertia
This is a force of resistance between 2 objects
Friction
This must occur for work to be done on an object
The object must move due to an external force
Acceleration and velocity in circular motion are directed _____ to each other.
Perpendicular
What law is associated with simple harmonic motion?
Hooke's Law
A 50 kilogram door has a torque of 250 N. Calculate the force applied to it
50N
What force must you push on a 2kg object against a vertical wall if the coefficient of friction is 0.4?
50N