Midterm Review Flashcards
What is the equation for constant velocity motion
Δx/s
In what way is a projectile using constant velocity motion
It is moving at constant velocity on the x-axis
In what way does a projectile accelerates
It accelerates downward on the y-axis
A ball is thrown straight upwards. What is the velocity of the ball at the very top of the path. The acceleration?
Velocity: 0 m/s
Acceleration: 9.8 m/s2
Three balls are launched from the top of a tall building. One is thrown downward with some velocity V. Another is thrown upwards with the same velocity V, and the last is dropped. Which hits the ground first?
The one thrown downward with some velocity because it starts out moving the fastest downward
Three balls are launched from the top of a tall building. One is thrown downward with some velocity V. Another is thrown upwards with the same velocity V, and the last is dropped. Which has the greatest acceleration?
They all have the same acceleration, g.
Three balls are launched from the top of a tall building. One is thrown downward with some velocity V. Another is thrown upwards with the same velocity V, and the last is dropped. Which will have the smallest (final) velocity?
The one dropped will have the smallest landing velocity because it starts with no velocity
A rock is thrown upward at 5 m/s at an angle of 25o. As it rises, what happens to the horizontal velocity of the rock? The vertical velocity?
As it rises, the horizontal velocity stays the same while the vertical velocity gets smaller until it hits zero
What is Newton’s First Law?
An object in motion will stay in motion. An object at rest will stay at rest unless acted on by an outside force
What is Newton’s Second Law?
F=ma
What is Newton’s Third Law?
For every action there is an equal and opposite reaction
How much is required to keep a 3.0 kg object moving at a constant velocity on a frictionless, airless surface
No force
If an object is at rest, are there no forces acting on it?
No, gravity and normal forces are acting on it, they just cancel each other out so there is no net force
Mechanical equliibrium
When net force is zero
A physics teacher hangs a bowling-ball pendulum from the ceiling. He lifts the ball back until it is at face level and lets go. If the teacher doesn’t lean forward, the ball won’t swing back and hit him in the face. Why not?
Because energy cannot be created or destroyed, after the bowling ball is released it cannot gain any more energy, so the most it can swing back up to is face-level.
