Chapter 1 about science 1. Differentiate between hypothesis and theory.

Transcription

1 Physics A Exam Review Name Hr PHYSICS SCIENTIFIC METHOD FACT HYPOTHESIS LAW THEORY PHYSICAL SCIENCE UNITS VECTOR MAGNITUDE FORCE MECHANICAL EQUILIBRIUM NET FORCE SCALAR RESULTANT TENSION SUPPORT FORCE STATIC DYNAMIC STATE OF MOTION INERTIA NEWTON S FIRST LAW FRICTION LAW OF INERTIA MASS WEIGHT INSTANTANEOUS SPEED NEWTON SPEED VELOCITY FREE FALL AVERAGE SPEED VECTOR ACCELERATION DISPLACEMENT KILOGRAM ACCELERATION OF GRAVITY POUND RELATIVE MOTION HORIZONTAL COMPONENT PROJECTILE FREEFALL HANG TIME VERTICAL ACCEL. VERTICAL COMPONENT PRESSURE RELATIVE VELOCITY PASCAL NEWTON S 2ND LAW NEWTON S 3RD LAW FRICTION INVERSELY PROPORTIONAL RECOIL DIRECTLY PROPORTIONAL STATIC FRIC. AIR RESISTANCE KINETIC FRIC. ACTION/REACTION PAIR COEFFICIENT OF FRIC. INTERACTION TERMINAL SPEED MOMENTUM IMPULSE LAW OF CONSERVATION OF MOMENTUM ELASTIC COLLISION INELASTIC COLLISION LAW OF CONSERVATION OF ENERGY WORK MECHANICAL ENERGY POTENTIAL ENERGY KINETIC ENERGY POWER MECHANICAL ADVANTAGE JOULE WATT EFFICIENCY ENERGY LEVER PULLEY Chapter 1 about science 1. Differentiate between hypothesis and theory. 2. Describe the scientific method. 3. For a scientific hypothesis to be valid, there must be a way of proving it. True False 4. Give examples of measurements that are: vectors: scalar: 5. What are the steps of the scientific method? chapter 2: Explain how to determine the resultant of two vectors a) in the same direction, and b)perpendicular to each other. What are the resultants for the following two vectors: What is a force? What are possible units for force?

2 2. Give 2 examples of a support force: 3. A cat lies on the floor, are there no forces on the cat? Is there a net force? 4. How much tension is in a rope that holds up a 20 N bag of candy? 8. What is true when an object is in equilibrium? 9. What are the tensions in the ropes below: 60 N 60 N 60 N 60 N 10. A scaffold that weight 300 N support two painter, one 400 N and the other 600 N. The tension in the left rope is 400 N, what is the tension of the right rope? 11. What is the difference between static and dynamic equilibrium? chapter 3- Newton s first law of motion-inertia 1. Without friction, how much force is necessary to keep an object moving? 2. If there is no net force how can what two states can a body be in? Can it be turning. 3. What determines how much inertia an object has? Does it change with speed? 4. How does inertia relate to the force required to change its state of motion? 5. Will 2 kilograms of feathers and 2 kilograms of rock have... a) the same mass b) the same weight c) the same volume 6. A gallon of milk is 5 kg: a) what is its weight in Newtons on Earth? b) What is its weight in N in deep space c) what is its weight in pounds on Earth? d) What is its mass on the moon? 7. Suzie weighs 500 N, what is her mass? 8. What causes whiplash? 9. Why do you wear a seat belt? 10. If you weighed 140 pounds on Earth, how much would you weigh on Jupiter where gravity is 26 m/s 2? Chapter 4- linear motion 1. What is the difference between instantaneous and average speed? 2. What is the equation for speed? What are some possible units for speed?

3 3. Differentiate between speed and velocity. 4. When does an object have constant velocity? 5. What is the motion equation for acceleration? 6. Give an example of an object traveling at a constant velocity and accelerating. 7. What are the three ways an object can accelerate? 8. What is free fall and how does it relate to gravity? 9. What is the value for the acceleration due to gravity? 10. In 10 seconds a cheetah can move 250 m. What is its speed? 11. A car changes from 5 m/s to 15 m/s in 4 seconds. What is its acceleration? Chapter 5 Projectiles 1. Define projectile. Give some examples of projectiles. 2. What happens to the vertical velocity of a projectile as time continues? What happens to the horizontal velocity? 3. Draw the path of a projectile. Label the horizontal and vertical velocities at a point going up, at a point going down, and at the top of the path. 4. Identify the relationship of different launch angles with a projectiles range (the horizontal distance traveled.) (ex: 15, 30, 45, 60, 75, 90 o ) 5. How far below an initial straight-line path will a projectile fall in one second? Two seconds? 6. If a ball is thrown up at 10 m/s, what will be the speed of the ball when it s caught back at the original point of the throw? 7. If you throw a ball straight up, what is the ball s instantaneous speed at the top of its path? What is the ball s acceleration at the top of its path? 8. How far does a ball drop in 1 s, 2s, 5s?

4 9. A car going 15 m/s,drives off a pier that is 4.0 m above the surface of the water. How far out from the pier does the car land? 10. A cannon is shot at an angle with a horizontal speed of 10 m/s and a vertical speed of 20 m/s. How long is the cannon ball in the air? How far does it go? Chapter 6 Newton s 2nd Law 1. What is the relationship between force and acceleration? 2. How does friction affect the motion of an object? 3. What determines the amount of friction between... a) solid on solid:, b) an object and air:, 4. What are two ways to increase the pressure on an object?, 5. If you push with 25 N on a 5 kg box and there is a 10 N force of friction, how fast will the box accelerate? 6. If an object moves with a constant velocity, what is the acceleration of the object? What is the net force acting on the object? 7. It takes 1.5 N to get a 0.60 kg block of wood to start sliding then it takes 1.2 N of pulling to keep the block moving at a constant velocity. What is the coefficient of static and kinetic friction?, 8. An 600 N skydiver (60 kg) jumps out of a plane and has 100 N of friction on him. What is his net force? What is his acceleration?. Chapter 7 Newton s 3rd Law 1. Can you have a single action on an object?explain: 2. Do action/reaction forces cancel each other out? Explain: 3. A box sits on a table. Are the weight of a box and the support force an action/reaction pair? Explain: 4. What makes the object move in each case: a) you swimming b) a bird flying c) tug of war 5. Why does a cannon and its ball have different accelerations if the forces are equal and opposite? 6. How does a rocket fly? Chapter 8-Momentum 1. Distinguish between mass and momentum. Which is inertia and which is inertia in motion?

5 2. When the force of impact on an object is extended in time, does the impulse increase or decrease? 3. In a car crash, why is it a good idea for an occupant to extend the time during which the collision takes place? 4. You are standing on a skateboard: a. When you throw a ball, do you experience an impulse? b. Do you experience an impulse when you catch a ball of the same speed? c. Do you experience an impulse when you catch it and then throw it out again? d. Which impulse is greatest? 5. What does it mean to say that momentum is conserved? 6. Distinguish between an elastic and an inelastic collision. 7. What is the momentum of an 6 kg bowling ball rolling at 2 m/s? 8. A bicycle and rider have a mass of 100 kg and are rolling at 4.0 m/s. If a 50 kg kid jumps on back, what is the new speed? 9. Why does it hurt more when an object bounces off of you? Chapter 9- Energy 1. How many joules of work are done on an object when a force of 10 N pushes it a distance of 10 m? 2. What are two ways to have a lot of power? 3. In which situation is more power required: Slowly lifting a book bag full of books up the stairs or quickly lifting the same book bag full of books up the same stairs? 4. How much power is required to do 100 J of work on an object in a time of 0.5 sec? 5. What are the two main forms of mechanical energy? 6. A 20 kg boulder is raised above the ground so that its potential energy relative to the ground is 200 J. Then it is dropped. What is its kinetic energy just before it hits the ground? How fast will it be moving just before it hits the ground? 7. What is the potential energy of a 10 kg box 10 m above the floor? 8. What is the kinetic energy of a 4 kg football traveling at 10 m/s? 20 m/s? 9. How much more force does it take to stop an object moving twice as fast? 10. Whenever work is done, it either changes an object s energy or energy.

6 means change in Momentum = m x V W = Fnetd PE = mgh m1v i + m2vi = m1vf + m2vf mv = mvf - mvi impulse = m v = Ft P = work time Work = KE + PE F x leverarm = F x leverarm KE = 1 mv 2 2 M.A. = output F input F