Physics BMAT Question

I can't do this... tried using momentum and speed equals distance/time... just not sure how to find force... do I use change in momentum /time? But I dunno the time... ?!

(edited 7 years ago)

Reply 1

RogerOxon

Original post by Uni12345678

I can't do this... tried using momentum and speed equals distance/time... just not sure how to find force... do I use change in momentum /time? But I dunno the time... ?!

Try thinking about the energy transfer.

Reply 2

Uni12345678

Original post by RogerOxon

Try thinking about the energy transfer.

okay... i got 9000J kinetic energy at the start... what do i do next?

Reply 3

RogerOxon

Original post by Uni12345678

okay... i got 9000J kinetic energy at the start... what do i do next?

Something does negative work on the bullet to cause it to lose kinetic energy.

P.S. You might want to check that kinetic energy calculation

Reply 4

Uni12345678

Original post by RogerOxon

Something does negative work on the bullet to cause it to lose kinetic energy.

P.S. You might want to check that kinetic energy calculation

ah i got it, the bush does work equal to the kinetic energy of the bullet in order to stop it. So you use work done= distance x force to work out the force the bush exerts. i got 3.75 x 10^3 :smile: