Physics of Motion
The difference between Speed and velocity
Speed refers to how fast an object is moving, only considering the magnitude of its motion, while velocity indicates both the speed and the direction of an object's movement
The unit for velocity
Meters per second
A ball on a string moving in a circle at constant speed still has this nonzero quantity.
acceleration (centripetal)
The unit for force
Newton
the acceleration due to gravity
What is 9.8 m/s^2
If an object is at the peak of its parabolic path, what is it's vertical velocity?
0 m/s
A hammer and a feather are dropped at the same time on the moon. They both reach the ground at the same time. Why?
There is no air, so all objects will fall at the same rate
A car moves in a circle at constant speed. Its acceleration points in this direction.
towards the center of the circle
The equation for Friction force.
F= μ Fn
In acceleration formula, what does Vi stand for?
Initial Velocity
If velocity and acceleration point in opposite directions, the object is doing this.
slowing down
Tyler runs the basketball court 5 times (from one side back to the other 5 times). Ending in his original starting place. What is Tyler's displacement at the end of his run?
0 meters. He ended where he started
When a string holding a spinning ball suddenly breaks, the ball moves in this direction immediately after.
tangent to the circle
Does your weight increase or decrease when traveling upward on an elevator?
What is Increases
The average acceleration formula
a=(Vf-Vi)/t
An object thrown straight up has this acceleration at the very top of its motion (ignoring air).
9.8 m/s^2
The area under a velocity–time graph represents this.
displacement
A car moving around a flat curve relies on this force to provide centripetal force.
friction
A 5 kg block is pulled on a frictionless horizontal plane at 5 m/s2. Find the tension in the string pulling it along if the string is at an angle of 30 degrees above the horizontal.
29 N
What is the definition of max static friction
The highest amount of friction force generated between two objects, just before it begins to slide.
If a tennis ball was thrown off the top of Elliot and hit the ground in 3.2 seconds, How fast will it be traveling when it hits the ground?
31.4 m/s
Otis has a mass of 45 kg; what is the scale reading when Otis is traveling upward at a constant velocity of 2 m/s on an elevator?
(45 )(9.81 ) = 441.45 N
Increasing the radius of circular motion while keeping speed constant changes centripetal acceleration in this way.
Two masses, m1 = 2 kg and m2 = 3 kg, are connected by a light string over a frictionless pulley. Find the acceleration of the system.
1.96 m/s^2
Find the equation for the velocity of an object in Earth's orbit.
v= √( (GM)/r )