Semester Test Review 12/11/2012

Transcription

1 An athlete sitting in a wheelchair at rest throws a basketball forward. Since the athlete and the wheelchair have greater mass than the basketball has, the athlete and the wheelchair will Semester Test Review A. move backward at a lower speed than the basketball moves forward B. travel the same distance as the basketball but in the opposite direction C. move backward at a higher speed than the basketball moves forward D. have the same forward velocity as the basketball Mary drives 200 miles at an average speed of 65 miles/hour. About how many minutes did it take her to get to her destination? If a quarter is flicked horizontally off of a desk at the same time another quarter is dropped from the same height, which quarter will land first? If a Rock A (1 kg) and a Rock B (2 kg) are both dropped from 40 feet high, which will land first? Garrett runs a distance of 3 miles in 25 minutes. What is his average speed? 1

2 According to Newton's second law, a bus is harder to push than a bike because If you apply a horizontal 40 N force to a 400 kg crate and friction applies a 15 N force against you, what is the acceleration of the crate? As Mattie is driving down the highway at a speed of 27 m/s, a car pulls out in front of her. She slams on her brakes slowing down to 10 m/s in 0.7 s. Calculate her acceleration. Ignoring air resistance, as a projectile moves along it path, the net vertical force is Ignoring air resistance, as a projectile moves along it path, the net horizontal force is A group of researchers discovered the fossilized remains of a flying mammal that appears to have lived 130 million to 165 million years ago. Since the earliest flying birds are believed to have appeared about 150 million years ago, researchers concluded that birds and mammals began to fly at about the same time. This conclusion would be most weakened by evidence of which of the following? A. A 100 million year old fossil of a flying bird B. A 120 million year old fossil of a flying bird C. A 160 million year old fossil of a flying mammal D. A 200 million year old fossil of a flying mammal 2

3 A circle graph would best help a student communicate a conclusion about an investigation involving A. the proportions by mass of three metals in one alloy B. the amounts of heat released by three chemical reactions C. the amounts of force required to accelerate three different masses D. the electrical conductivity of three salt solutions Which of the following information would allow the most direct calculation of the average speed on the upward flight of a tennis ball thrown straight up in the air? A. force and wind speed B. maximum height and the time it takes the ball to reach that height C. ball mass and time it takes to reach highest point D. force and time it takes ball to fall to the ground Draw a motion diagram for: A. constant velocity B. acceleration C. deceleration As Ed sits on a bus that is traveling east 8 m/s, John walks up the aisle toward the driver at 2 m/s. Sally walks toward the back of the bus at 3 m/s. Andy stands outside on the sidewalk, watching the bus go by. A. How fast does Ed perceive John to be moving? B. How fast does Andy perceive Sally? If a Ferrari, with an initial velocity of 10 m/s, accelerates at a rate of 30 m/s/s for 3 seconds, what will its final velocity be? A lizard accelerates from 2 m/s to 15 m/s in 5 seconds. What is the lizard s average acceleration? 3

4 A cannonball is shot off of a cliff horizontally at 12 m/s and lands at the base of the cliff 3 seconds later. How far from the base of the cliff does the cannonball land? What does acceleration/deceleration look like on a position time graph? a velocity time graph? What does constant positive/negative velocity look like on a position time graph? Velocity time graph? How do you calculate the average velocity using a position time graph? Inertia is dependent on?. Which of the following objects have the greatest inertia? A. 2 kg ball rolling 3 m/s B. 4 kg ball rolling 1 m/s C. 1 kg ball at rest D. 5 kg ball at rest 4

5 A 2.25 kg fish swims in a pond at a constant rate of 56 meters in 96 seconds. What is the fish s approximate speed? A student investigates the effects of five brands of fertilizer on plant growth and concludes that Brand X works best. Which of the following would best communicate this conclusion? A. A list of the ingredients in each brand of fertilizer used B. A graph showing the growth rate of plants grown with the different fertilizers C. A description of the role of different nutrients in plant growth D. A diagram showing the conditions in which each plant grew What is the net force exerted on a 90.0 kg race car driver while the race car is accelerating from 0 to 44.7 m/s in 4.50 s? John has a mass of 90 kg. Calculate John's weight. Draw a free body diagram that represents a car accelerating to the right? A 2 kg bucket hangs from a rope. Calculate the tension on the rope. 5

6 A 0.5 kg ball is tied to a 0.25 m string and swing in a circle. If it takes 0.2 s for the ball to go around one time, what is the centripetal acceleration? The moon revolves around the earth. What type of force is acting as the centripetal force that causes the moon to follow its curved path? Give an example of tension force acting as the centripetal force. Inertia can best be described as?. Two bowling balls each have a mass of 7.2kg. They are located next to each other with their centers 0.4 m apart. What gravitational force do they exert on each other? 1. Name of acceleration? 2. Direction of acceleration? 3. Name of force? 4. Direction of force? 5. Name of velocity? 6. Direction of velocity? A rock is tied to a string and swung in a circle. If the string were to break, in what direction would the rock fly? 6

7 True or False? A little boy pulls a wagon with his dog in it. The mass of the dog and wagon together is 45 kg. The wagon accelerates at 0.85 m/s 2. What force is the boy pulling with? 1. A projectile has a vertical acceleration. 2. A projectile acts under the influence of gravity. 3. A projectile must be traveling downward. 4. A projectile's path is called its trajectory.. A 68 kg runner exerts a force of 59 N. What is the acceleration of the runner? Billy hiked 5 km east of his campsite and then 5 km north of his campsite. What is his displacement? What happens to the force of attraction between two objects if the distance between the objects increases? What if the mass of the two objects increase? Draw a diagram of a projectile that illustrates both the horizontal and vertical velocities at 7 different points. 7

8 If an object has a net force of zero, it Draw a free body diagram that represents an object in equilibrium? A. may be at rest or moving at a constant velocity. B. must be at rest. C. may be accelerating. D. must be decelerating. Ronnie has a weight of 500 N. Calculate Ronnie's mass. A bowling ball rolls off of the empire state building. Ignoring air resistance, the vertical velocity after the ball has been falling for three seconds is about When the air is released from a balloon, the air moves in one direction, and the balloon moves in another direction. Which law does this situation best illustrate? A student uses a hot plate, a thermometer, and a stopwatch to investigate the rate at which a metal object conducts heat. To ensure the most reliable results, which of the following should the student do? A. Perform a second investigation using different tools B. Use several thermometers to measure temperature C. Develop a hypothesis before starting the investigation D. Repeat the entire investigation several times 8