carbohydrate catabolism and other metabolism tests

Unit 8: Impulse-Force Model (Momentum) Moodle Homework www.aeak12online.org For all problems, assume the positive (+) direction is to the right or East. Negative (-) is West. Be sure to use a negative (-) sign to indicate direction. Don’t type a positive (+) if the answer is positive. A ball of mass 3.0 kg, moving at 2 m/s eastward, strikes head-on a ball of mass 1.0 kg that is moving at 2 m/s westward. The balls stick together after the impact. What are the magnitude and direction of the velocity of the combined mass after the collision? One way of measuring the muzzle velocity of a bullet is to fire it horizontally into a massive block of wood placed on a cart. Assuming no friction, we then measure the velocity with which the wood containing the bullet and cart begin to move. In one experiment the bullet had a mass of 50. g and the wood and its cart had a mass of 10. kg. After the shot, the cart, wood, and bullet moved at a constant speed, traveling 0.80 m in 0.40 s. From this data determine the original speed of the bullet. A raft of mass 180 kg carries two swimmers of mass 50. kg and 80. kg. The raft is initially floating at rest. The two swimmers simultaneously dive off opposite ends of the raft, each with a horizontal velocity of 3 m/s. With what velocity and in what direction does the raft start to move? A golf ball that weighs 0.45 N is dropped from a height of 1.0 m. Assume that the golf ball has a perfectly elastic collision with the floor. Determine the speed the ball had when it hit the floor. Suppose that the golf ball was in contact with the floor for 4.0 x 10-4s. What was the average force on the ball while it was in contact with the floor? (round to 1 decimal point) Old cannons were built on wheeled carts, both to facilitate moving the cannon and to allow the cannon to recoil when fired. When a 150 kg cannon and cart recoils at 1.5 m/s, at what velocity would a 10.0 kg cannonball leave the cannon? Complete a conservation of momentum diagram for firing one of these cannons. Find the velocity of the cannonball. (MOODLE Q) On an icy road, a 5000 kg truck rear-ends a 1200 kg car that had been traveling at 13 m/s, causing the truck to slow from 14 m/s to 12 m/s and the car to speed up. Complete the momentum conservation diagram for the accident. Find the final velocity of the car. (MOODLE) A tennis player’s 1.0 kg racket is moving with a velocity of 32 m/s when it impacts a tennis ball traveling at 35 m/s from the opponent’s serve. The 58 g ball is hit straight back at 25 m/s. What is the force the ball is hit back towards the opponent if the racket and ball are in contact for 0.08 seconds? A 90kg hockey player makes an illegal check by ramming an 80kg player at 6 m/s and slows to 4m/s after the collision. The 80kg player had been traveling at 2 m/s toward the 90 kg player before the collision. Find the velocity of the 80 kg player after the collision. Assume that the frictional forces on the players are small enough that the only net force on the players is due to the collision. It is very helpful to diagram this out. How long does it take an upward force of 100 N acting on a 50-kg rocket to increase its speed from 100 m/s to 150 m/s? What braking force is needed to bring a car having a mass of 1000-kg and moving 30 m/s to a stop in 60 seconds after the breaks are applied? A braking force is applied to a 300 kg motorcycle to reduce its speed from 20.0 m/s to 16.0 m/s in 10.0 s. What is its change in momentum? What force acted on the cycle? (MOODLE) A ball of mass 0.20 kg is pitched to a batter at 30 m/s and hit back toward the pitcher at 20 m/s. If the ball and bat were in contact for 0.25 s, what force was exerted on the ball? A soccer player kicks a soccer ball with a mass of 0.43-kg and accelerates it from rest to 30 m/s with a force of 100-N. How long must the foot be in contact with the ball? Moving at 20 m/s, a car of mass 700 kg collides with a stationary truck of mass 1400 kg. If the two vehicles interlock as a result of the collision, what is the after-collision velocity of the car-truck? A 0.50 kg ball traveling at 6 m/s collides head-on with a 1.0 kg ball moving in the opposite direction at –12 m/s. The smaller ball bounces backward at –14 m/s after the collision. Find the velocity of the larger ball after the collision. Draw a diagram! 523494010350500Two spring apart carts sit together on a frictionless track. After the plunger is released, one cart (1.5 kg) moves to the right with a speed of 2.7 m/s. If the other cart has a mass of 4.5 kg, how fast and in which direction will it move? A 0.530-kg basketball hits a wall head-on with a forward speed of 18.0 m/s. It rebounds with a speed of 13.5 m/s. The contact time is 0.100 seconds. Determine the impulse with the wall. a. Determine the force of the wall on the ball. (Moodle question; round to nearest whole number) The amount of momentum an object possesses depends upon two quantities. What are the two quantities? Select two answers. a. The mass of the object. b. The speed of the object. c. The weight of the object. d. The acceleration of the object. e. The direction that the object is moving. If an object has momentum, then one can be sure that the object is ______. List all that apply in alphabetical order with no commas or spaces between letters. a. moving b. moving fast c. speeding up d. slowing down e. encountering a net force Consider the mass and velocity values of Objects A and B below. Compared to Object B, Object A has ____ momentum. 24517355588000 a. two times the b. four times the c. six times the d. eight times the e. the same ab. one-half the ac. one-fourth the ad. one-sixth the ae. one-eighth the Which one of the following is a unit of momentum? a. m/s b. kg/s c. kg • m/s d. kg • m/s2 An object is moving to the left at a constant speed. What is the direction of the momentum vector? a. The momentum vector is directed leftward. b. The momentum vector is directed rightward. c. Nonsense! Momentum is not a vector. It does not have a direction. d. Nonsense! An object moving with a constant speed does not have a momentum. An object is moving to the right and slowing down. What is the direction of the momentum vector? a. The momentum vector is directed leftward. b. The momentum vector is directed rightward. c. Nonsense! Momentum is not a vector. It does not have a direction. d. Nonsense! An object that is changing speed does not have a momentum. Which of the following objects have momentum? Include all that apply. a. An electron is orbiting the nucleus of an atom. b. A UPS truck is stopped in front of the school building. c. A Yugo (a compact car) is moving with a constant speed. d. A small flea walking with constant speed across Fido's back. e. The high school building rests in the middle of town. A truck driving along a highway road has a large quantity of momentum. If it moves at the same speed but has twice as much mass, its momentum is ________________. a. zero b. quadrupled c. doubled d. unchanged Consider a karate expert. During a talent show, she executes a swift blow to a cement block and breaks it with her bare hand. During the collision between her hand and the block, the ___. time of impact on both the block and the expert's hand is the same force on both the block and the expert's hand have the same magnitude impulse on both the block and the expert's hand have the same magnitude all of the above. none of the above. In order to catch a ball, a baseball player naturally moves his or her hand backward in the direction of the ball's motion once the ball contacts the hand. This habit causes the force of impact on the players hand to be reduced in size principally because ___. the resulting impact velocity is lessened the momentum change is decreased the time of impact is increased the time of impact is decreased none of these Suppose that you're driving down the highway and a moth crashes into the windshield of your car. Which undergoes the greater change is momentum? a. the moth b. your car c. both the same Suppose that you're driving down the highway and a moth crashes into the windshield of your car. Which undergoes the greater force? a. the moth b. your car c. both the same Suppose that you're driving down the highway and a moth crashes into the windshield of your car. Which undergoes the greater impulse? a. the moth b. your car c. both the same Suppose that you're driving down the highway and a moth crashes into the windshield of your car. Which undergoes the greater acceleration? a. the moth b. your car c. both the same A 5-N force is applied to a 3-kg ball to change its velocity from +9 m/s to +3 m/s. This impulse causes the momentum change of the ball to be ____ kg•m/s. a. -2.5 b. -10 c. -18 d. -45 e. none of these A 5-N force is applied to a 3-kg ball to change its velocity from +9 m/s to +3 m/s. The impulse experienced by the ball is ____ N•s. a. -2.5 b. -10 c. -18 d. -45 e. none of these When a mass M experiences a velocity change of v in a time of t, it experiences a force of F. Assuming the same velocity change of v, the force experienced by a mass of (1/2)M in a time of 4t is ____. a. 2F b. 8F c. (1/2)*F d. (1/8)*F e. none of these When a mass M experiences a velocity change of v in a time of t, it experiences a force of F. Assuming the same velocity change of v, the force experienced by a mass of 2M in a time of (1/2)t is ____. a. 2F b. 4F c. (1/2)*F d. (1/4)*F e. none of these Cars are equipped with padded dashboards. In collisions, the padded dashboards would be safer than non-padded ones because they ____. List all that apply. a. increase the impact time b. decrease an occupant’s impulse c. decrease the impact force d. none of the above