1) Suppose a projectile's speed and mass are both doubled. Its momentum will then be
a quadrupled
b unchanged
c halved
d none of these doubled
2) Two equal-mass bullets traveling with the same speed strike a target. One of the bullets is rubber and bounces off: the other is metal and penetrates, coming to rest in the target. Which exerts the greater impulse on the target?
a both exert the same
b the rubber bullet
c not enough information
d none of these
e the metal bullet
3) A bomb hanging from a string explodes into pieces of different sizes and shapes. After the explosion
a the momentum of all the pieces, exhaust, and smoke adds up to zero
b not enough information to comment
c the vector momentum of each piece is identical
d the total momentum is increased
e none of these
4) A can of whipped cream floating in space develops a hole in the bottom from which it squirts backward a mess of gas and cream at a constant speed with respect to the can. The can thereupon
a moves forward at a constant speed
b accelerates forward throughout the squirting
c first speeds up, and then slows down when the gas runs out
d remains at rest
e none of these
5) Two cars, each of 1570 kg, collide. One is heading north at 22.0 m/s while the other is traveling east at 22.0 m/s. If on impact they mash together and skid off as one, in what direction will the wreckage travel?
a none of these
b east
c 22.5° north of east
d 45° north of east
e 45° north of west
please help =D thanks all
a quadrupled
b unchanged
c halved
d none of these doubled
2) Two equal-mass bullets traveling with the same speed strike a target. One of the bullets is rubber and bounces off: the other is metal and penetrates, coming to rest in the target. Which exerts the greater impulse on the target?
a both exert the same
b the rubber bullet
c not enough information
d none of these
e the metal bullet
3) A bomb hanging from a string explodes into pieces of different sizes and shapes. After the explosion
a the momentum of all the pieces, exhaust, and smoke adds up to zero
b not enough information to comment
c the vector momentum of each piece is identical
d the total momentum is increased
e none of these
4) A can of whipped cream floating in space develops a hole in the bottom from which it squirts backward a mess of gas and cream at a constant speed with respect to the can. The can thereupon
a moves forward at a constant speed
b accelerates forward throughout the squirting
c first speeds up, and then slows down when the gas runs out
d remains at rest
e none of these
5) Two cars, each of 1570 kg, collide. One is heading north at 22.0 m/s while the other is traveling east at 22.0 m/s. If on impact they mash together and skid off as one, in what direction will the wreckage travel?
a none of these
b east
c 22.5° north of east
d 45° north of east
e 45° north of west
please help =D thanks all
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1) Momentum is mass x velocity. If you double both mass and velocity you quadruple the momentum. (Right? 2 x 2 = 4, double each - and 4 x 4 = 16... 4 times as much. (A)
2) The metal bullet was just slowed down by the target. The rubber bullet was slowed down, stopped, and accelerated back in the direction it came from. (B)
3) (A) is the right choice: Visualize the explosion as an event which happens at a single (theoretical) point and sends its force out uniformly. Every piece going off to the right will be balanced by one or two going left....
4) I'm going with (B). The "stuff" being expelled from the can will be an action. The reaction will be a force pushing the can - accelerating the can - forward. As there no "drag" in space, the can will continue to accelerate for as long as the squirting continues.
5) This is, basicaly, a vector question. The two masses are the same. The two speeds are the same.
So, draw one arrow to the east, an identical arrow to the north and find the resultant. Yes, you'll have drawn a square - and the resultant is the diagonal going off directly to the N-E Go with (D)
2) The metal bullet was just slowed down by the target. The rubber bullet was slowed down, stopped, and accelerated back in the direction it came from. (B)
3) (A) is the right choice: Visualize the explosion as an event which happens at a single (theoretical) point and sends its force out uniformly. Every piece going off to the right will be balanced by one or two going left....
4) I'm going with (B). The "stuff" being expelled from the can will be an action. The reaction will be a force pushing the can - accelerating the can - forward. As there no "drag" in space, the can will continue to accelerate for as long as the squirting continues.
5) This is, basicaly, a vector question. The two masses are the same. The two speeds are the same.
So, draw one arrow to the east, an identical arrow to the north and find the resultant. Yes, you'll have drawn a square - and the resultant is the diagonal going off directly to the N-E Go with (D)
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O.o wth?>