momentum forumula questions

[Zuloft]

i have 3 problems for homework and im stomped. i dont know if the way im solving the problem is right. im using the FT=MV forumla for all 3 problems.


1) a football player of mass 120 kg is travelling at 20 m/s collides with another player and comes to rest in 1.5 s. what is the force of impact?

2) a golf ball of mass 0.050 kg acqyuires a speed of 80 m/s when hit with a force of 3.0 x 10 ^3 n. how long was the club in contact with the ball

3) what force acting for 1.36 x 10 ^-3 will change the velocity of a 95 g baseball from 50.0 m/s east to 45 m/s west?


thanks!? but i just need confirmation on what formula to use.

[Hootenanny]

just to clarify when you say FT=MV you do mean Ft=M\Delta V?

[Zuloft]

correct i couldnt find the delta symbol

[Mindscrape]

Yeah, using F=\frac{\Delta P}{\Delta t} will work for all three.

[Zuloft]

http://physicsforums.com/latex_images/88/884080-0.png


can i use that though?

[Mindscrape]

http://physicsforums.com/latex_images/88/884080-0.png
can i use that though?
There isn't any difference between them, other than algebra manipulatioon. \Delta P = m \Delta v since mv is the definition of momentum, and mass is a constant.