Physics Exam 2 Study Guide Questions with Correct Answers (Latest Version) Guaranteed to get an A.

Physics Exam 2 Study Guide Questions with Correct Answers (Latest Version) Guaranteed to get an A. A same-size iron ball and wooden ball are dropped simultaneously from a tower and reach the ground at the same time. The iron ball has a greater momentum A 1000-kg car and a 2000-kg car are hoisted to the same height. Raising the more massive car 2) requires twice as much work The total momentum of a flock of identical birds could be zero only if the birds are flying in different directions The average braking force of a 1000-kg car moving at 10 m/s braking to a stop in 5 s is 2000 N A feather and a coin dropped in a vacuum fall with equal accelerations If several balls are thrown straight up with different initial speeds, the quantity that will have the same value along their paths is their acceleration Both a 50-kg sack is lifted 2 meters from the ground and a 25-kg sack is lifted 4 meters in the same time. The power expended in raising the 50-kg sack is the same When you jump from an elevated position you usually bend your knees upon reaching the ground, which makes the time of the contact about 10 times that of a stiff-legged landing. In this way the average force your body experiences is about 1/10 as great Which task requires more work? -lifting a 50kg sack 2 meters -lifting a 25kg sack 4 meters both the same When Peter tosses an egg against a sagging sheet, the egg doesn't break due to -reduced impulse -reduced momentum neither A toy elevator is raised from the ground floor to the second floor in 20 seconds. The power needed using 1000 J of work, is 50 W A heavy truck and a small car rolling down a hill at the same speed are forced to stop in the same amount of time. Compared with the force that stops the car, the force needed to stop the truck is greater A 2-kg ball is held 4 m above the ground. Relative to the ground its potential energy is 80 J When a drawn bow of potential energy 40 J is fired, the arrow will ideally have a kinetic energy of 40 J A bungee jumper attains a speed of 30 m/s just as the bungee cord begins to stretch. If the period of stretch is 2 s while coming to a halt, the jumper's average deceleration is about 1.5g The change in momentum that occurs when a 1.0 kg ball traveling at 4.0 m/s strikes a wall and bounces back at 2.0 m/s is 6kg m/s You're driving down the highway and a bug spatters into your windshield. Which undergoes the greater change in momentum during the time of contact? both the same A 2-kg rifle that is suspended by strings fires a 0.01-kg bullet at 200 m/s. The recoil velocity of the rifle is about 1 m/s The work done in pushing a TV set a distance of 2 m with an average force of 20 N is 40 J` Two identical gliders slide toward each other on an air track. One moves at 1 m/s and the other at 2 m/s. They collide, stick, and moves at 1/2 m/s Two vehicles with equal magnitudes of momentum traveling at right angles to each other undergo an inelastic collision. The combined wreck moves in a direction at 45 degrees to the direction of either car before collision If a Ping-Pong ball and a golf ball both move in the same direction with the same amount of kinetic energy, the speed of the Ping-Pong ball must be -less than the golf ball -more than the golf ball - the same both the same About 40 J is required to push a crate 4 m across a floor. If the push is in the same direction as the motion of the crate, the force on the crate is about 10 N When you and your snowboard are in motion, which of the following can be zero? -kinetic energy -inertia -momentum -mass -n/a na. Horses with the greatest linear speed on a merry-go-round are located near the outside When a twirling ice skater brings her arms inward, her rotational speed increases two identical arrows, one with twice the speed of the other, are fired into a bale of hay. Compared with penetration of the slow arrow, the faster arrow penetrates 4 times as far If a turntable's rotational speed is doubled, then the linear speed of a pet hamster sitting on the edge of the record will double Centripetal force does no work on a circularly-moving object because centripetal force has no component in the direction of motion. The rotational inertia of your leg is greater when your leg is straight A difference between linear momentum and angular momentum involves -a radial distance -two types of speed both If Alex wishes to rotate his skateboard, then he must apply a -rotational maneuver -torque -pause before bearing down on the board torque The circumference of a bicycle wheel is 2 meters. If it rotates at 1 revolution per second then its linear speed is 2 m/s A ball that gains speed as it rolls down a hill experiences a -net force -net torque both For a system in mechanical equilibrium, the resultant -force must be zero -torque must be zero both on a balanced seesaw, a boy three times as heavy as his partner sits -1/3 distance from the fulcrum -less than 1/3 -more than 1/3 1/3 distance If the speed of a bicycle is reduced to half before skidding to a stop, it will skid 1/4 as far If the speed of a motor scooter doubles, which of the following also doubles? -kinetic energy -momentum -acceleration momentum A coin and a ring roll down an incline at the same time. The one to first reach the bottom is the coin A flywheel's diameter is twice that of another of the same shape and mass. Rotational inertia of the larger flywheel is 4x as greater The net force exerted on a car traveling in a circular path at constant speed is directed toward the center of the center A jack system will increase the potential energy of a heavy load by 1000 J with a work input of 2000 J. The efficiency of the jack system is 50% a machine puts out 100 watts of power for every 1000 watts put into it. The efficiency of the machine is 10% A hydraulic press has its input piston depressed 20 centimeters while the output piston is raised 1 centimeter. A 1-newton input can lift a load of 20 N The bob of a simple pendulum has its maximum kinetic energy at the bottom of the swing After rolling halfway down an incline, a marble's kinetic energy is the same A hydraulic jack is used to lift objects such as automobiles. If the input force is 200 N over a distance of 1 meter, the output force over a distance of 0.1 meter is ideally 2000 N The concept of pressure involves both force and area Which will remain the same for two identical books, one lying flat and the other standing on an end? -weight -pressure weight When you stand with only one of your feet on a weighing scale, the scale reading is the same with both feet Sara lies on a bed of sharp nails without harm because her weight is distributed over hundreds of nails While standing, your blood pressure is normally greatest in your feet A dam is thicker at the bottom than at the top mainly because water pressure increases with depth Buoyant force acts upward on a submerged object because pressure against its bottom is greater than pressure against its top. A completely submerged object always displaces its own volume The buoyant force acting on a 10-ton ship floating in the ocean is 10 tons When an object is partly or wholly immersed in a liquid, it is buoyed up by a force equal to the weight of liquid displaced. The reason a life jacket helps keep you afloat is the density of both you and the jacket together is less than your density alone Buoyant force is greater on a submerged 1-cubic centimeter block of -lead -aluminum -both the same Compared to the density of water, the density of a fish is same P=mv momentum=mass x velocity I=Ft impulse=force x time I=deltaP impulse-momentum theorem=change in momentum=impulse applied a freight train rolls along track with considerable momentum. if it rolls at the same speed but has twice as much mass, its momentum is.. doubled a 4kg ball has a momentum of 12kg m/s. what is the ball's speed? 3 m/s the impulse-momentum relationship is a direct result of... newton's second law how can you catch a softball with your bare hand? increase time of catch why doesnt a wine glass break on a carpet floor? longer time to stop a 1000kg car moving at 10 m/s that brakes to a stop in 5s has an avg braking force of... 2000 N a 1000 kg car and a 2000 kg car are hoisted to the same height. Raising the more massive car requires twice as much work an object has gravitational potential energy due to its height above the ground an object that has kinetic energy must be moving