I need some help with these conceptual questions? Please help!?

Question

5. U r standing perfectly still & then u take a step forward. Before the step your momentum was 0, but aftereward u have some momentum. Is the conservation of momentum violated in this case? (what is the conservation of momentum?)

12. U r watching a movie about a superhero & notice that the superhero hovers in the air & throws a piano at some bad guys while remaining stationary in the air. What's wrong with this scenario? (I rlly don't know).

13. In golf, novice players are often advised to be sure to "follow through" w/ their swing. Why does this make the ball travel a longer distance if a shot is taken near the green, little follow-through is required. Y? (Again, I need help ppl).

15. A sharpshooter fires a rifle while standing w/ the butt of the gun against his shoulder. if the forward momentum of a bullet is the same as the backgward momentum of the gun, y isn't it as dangerous to be hit by the gun as by the bullet?

Last one:

16. A large bedsheet is held vertically by 2 students. A 3rd student, who happens to be the star pitcher on the baseball team, throws a raw egg at the sheet. Explain y the egg doesn't break when it hits the sheet, regardless of its initial speed.

I did all the other ones I had to do but these are the ones I don't quite get! ... &, if you're wondering why I wont' just ask my "teacher," it's because she doesn't know how to teach/explain things to us. I am a straight A student but I have a C in her class ... She ruined my GPA... Some students asked her for help (I was one of them)... We left her room w/out learning a single thing!

Answer 1

5. conservation of momentum means that momentum energy doesn't just appear or disappear

a simple example of the concept would be if a heavy train, with lots of momentum were two collide head-on with a small car, the train would continue forward, but at a slower speed, the new momentum of the train being reduced by the value of the momentum of the car in the opposite direction

taking a step, of course, does not violate conservation of momentum,

12. if the superhero throws a car forward, there should be an equal an opposite reaction of the superhero moving backward

if the hero weighs less than the car, he should move back faster than the car moved forward

of course, if the hero can fly, he can push himself forward in the air, and he should be able to use his flying power to cancel his motion and so, in superhero world there is nothing wrong, but in our world we expect an opposite reaction

13. follow through, means the club will stay in contact with the ball longer

the only time the club is accelerating the ball, obviously, is when it is actually contacting the ball, if that contact time is extended, then the velocity imparted to the ball is greater, and of course it then travels farther

15. notice that this is the same situation as the super hero, the bullet goes forward, so the gun has to go backwards

because the gun is much heavier than the bullet, the velocity of the gun backwards is much less than the velocity of the bullet, and because the gun stock is bigger than the bullet, the force of the blow is distributed over a wide area (you could picture if the gun stock was a pointed nail instead it might hurt when it backfired)

Answer 2

these are all conservation of momentum questions. momentum (p) = mass x velocity
what it says is that the momentum before some event is equal to the momentum after the event. the catch is that this must be in a system free from friction.
5. momentum is conserved. when you walk you impart an equal amount of momentum onto the earth. only it is so large there is no visible change.
12. if superman throws a guy, you would expect him to go backwards with the same momentum as the guy he threw forwards, that way they cancel eachother out. example: in space an astronaut is trying to get back on his ship. all he has is a wrench. he throws the wrench in the opposite direction to where he wants to go and he moves towards the ship because momentum must be conserved.
but because the wrench is so light, it moves away quickly whilst the astronaut moves away slowly. this is the same story as with shooting a gun. whilst the bullet moves very quickly, it has a very small mass and so, its total momentum is not that great. the gun is heavier and moves at amuch slower rate.

Answer 3

In Q5 The "conservation of momentum" relates to your not spending (conserving) the kinetic energy.

Q12 relates to a "Hollywood"-created idea. Humans or "Superheros" normally do not have the strength to throw an item as large as a piano. - Yes, I am diminishing the Superheroic strength of SUPERMAN (I am sorry.)

Q13. Wherever the golf shot is made does make a difference as to how much follow-through is advised.
When a golf shot is made, following-through with the swing creates an "internal motion-potential" that causes the golf ball to continue moving, whereas a "jerky" (push-and-stop) type of swing does not provide this effect (commonly for closer shots.)

Q15. Because the bullet has more of a "piercing" effect when it strikes it's target. Scientific research has been taken on the trajectory-effects of bullets as specific types and designs of bullets actually speed up as they travel from the gun to the target. - And the distance from the butt of the gun to the shoulder should be 0 so as to avoid injury to the shoulder.

Answer 4

The easiest way to learn golf like a pro is by following "The Simple Golf Swing" program. It's primarily a 31 page eBook that teaches golfers how to make solid contact with the ball, how to avoid hitting fat, how to avoid slicing, how get more power, accuracy, and consistency in your swing. Consistency being the number 1 golf skill.

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Answer 5

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Answer 6

dude there's not enough space here, but if you email me ,and give me the best answer to this first, I will send you information about how this answer is defined...