Physics 1050 Test 1

-if air resistance is negligible, which ball will have the greater speed when it strikes the ground below?
--both will strike the ground below at the same time

-which of the following has the largest momentum relative to earth?
--a pickup truck speeding along the highway

-a rifle recoils from a firing bullet. the speed of the rifle is small because
--rifle has more mass than the bullet

-when a rifle is fired, it recoils so both the bullet and the rifle are set in motion. the rifle and bullet ideally acquire equal
--but opposite amounts of momentum

-a rifle has a mass of 2kg is suspended by strings. the rifle fores a bullet of mass 1/100 kg at a speed of 200m/s. the recoil velocity of the rifle is about
--1 m/s

-a 30 kg girl and a 25 kg voy face each other on friction-free roller blades. the girl pushes the boy, who moves away at a speed of 1.0 m/s. the girl's speed is
--0.83 m/s

-a 5000 kg freight car runs into a 10,000 kg freight car at rest. the couple upon collision and move with a speed of 2 m/s. what was the initial speed of the 5000 kg car?
--6 m/s

-a car moves 4 times as fast as another identical car. compared to the slower car, the faster car has
--16 times the KE

-a TV set is pushed a distance of 2 m with a force of 20 N that is in the same direction as the set moves. how much work is done on the set>
--40J

-when a car is braked to a stop, its kinetic energy is transformed to
--heat

-a 1000 kg and a 2000 kg car are hoisted the same distance in a gas station. raising the more massive car requires
--twice as much work

-when an object is lifted 10 m, it gains a certain amount of potential energy. if the same object is lifted 20 m, its potential energy gain is
--twice as much

-if you push an object twice as far while applying the same force, you do
--twice as much work

-a person on the edge of a roof throws a ball downward. it strikes the ground with 100 J of kinetic energy.  the person throws another identical ball upward with the same initial speed, and this too falls to the ground. neglecting air resistance, the second ball hits the ground with a kinetic energy of
--100 J

-a 51 kg diver steps off a diving board that is 10 m above the water. the diver hits the water with kinetic energy of
--5000 J

-does the KW of a car charge more when it goes from 10 to 20 km/h or when it goes from 20 to 30 km/h?
--the KE changes more from 20 to 30 km/h