Semester 1 Concept Questions

Period 1 has covered (and therefore needs to know) #1-30;

Period 2 – 4 has covered (and therefore needs to know) #1-21

  1. What is the equation for constant velocity motion?
  1. In what way is a projectile (a ball thrown at 30o, for example) using constant velocity motion.
  1. In what way is a projectile accelerating?
  1. A ball is thrown straight upwards. What is the velocity of the ball at the very top of it’s path? What is the acceleration of the ball at the very top of it’s path?
  1. 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.
  2. Which hits the ground first? Why?
  3. Which has the greatest acceleration? Why?
  4. Which will have the smallest landing (final) velocity? Why?
  1. 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?
  1. What is Newton’s 1st Law? Give an example.
  1. What is Newton’s 2nd Law? Give an example.
  1. What is Newton’s 3rd Law? Give an example.
  1. How much force is required to keep 3.0 kg object moving at a constant velocity on a frictionless, airless, surface?
  1. Bart is taking the elevator from the first floor up to the roof. At first Bart feels lighter than he usually is, then he feels his normal weight, and then he feels heavier than he usually is. How do Newton’s laws explain this phenomenon?
  1. If an object is at rest, can it be conclude that it has no forces acting on it? Explain.
  1. What does it mean to be in mechanical equilibrium?
  2. A smart car travels down the road at a constant velocity towards a Mini Cooper. If the cars have the same mass and the same velocity, what is their total momentum when they are traveling towards each other? What will be their final momentum if the cars crash and become an entangled metal-plastic mass?
  1. Gun ammunition is put into an oven and the oven is then turned on. If the bullet is in a gun, the bullet becomes dangerous. However, if the bullet is by itself, it is the light metal casing that is more dangerous. Why?
  1. A physics teacher hangs a bowling-ball pendulum from the ceiling. He lefts 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?
  1. If jumping from a 20 foot high building, why is it better to land on a mattress a foot thick than a pile of wood one foot thick? (Use physics terms to explain.)
  1. A box is sliding across a frictionless surface when a cat falls vertically into it. What happens to the horizontal velocity of the box?
  1. Explain why you slide to the right side of the car when the car makes a left hand turn?
  1. Explain why astronauts feel weightless when they are in space.
  1. When a car rounds a turn, what force provides the centripetal force allowing the car around the turn?
  1. When spinning on a tire swing, a child spins really slow when her legs are out and the speed of spin increases when she pulls her legs in. Why does this happen?
  1. A ruler with weights hanging off it will balance if you place your finger at the 72 cm mark. Where is the center of mass of the ruler?
  1. What is the 1st law of thermodynamics?
  1. If work is being done on a system with an isothermal process, what much happen to the heat of the system?
  1. Explain how a heat engine works. Give an example of the heat engine.
  1. What is the 2nd law of thermodynamics and what implications does it have for heat engines?
  1. What is the 2nd law of thermodynamics as it applies to entropy.
  1. What are two ways to decrease the entropy of a system?
  1. Explain, using entropy, why a heat engine cannot be 100% efficient.