physics hw help asap!! please!!

[cc21392001]

48. A block of mass 0.6 kg slides 6.0 m down a frictionless ramp inclined at 20 degrees to the horizontal. It then travels on a rough horizontal surface where coefficient of kinetic friction is 0.50.
a) what is its speed after traveling 1.00 m on the rough surface?
b) what distance does it travel on this horizontal furface before stopping?

ok someone already explained it to me, but i didn't understand the explanation. basically i found the force of friction acting on the block and subtract it from the total energy. then i don't know wut to do. please help me. i'm completely lost on part b.

thank you

[enigma]

Hi cc,

Can you post what you've tried?

[cc21392001]

well for the first one i found the frictional force that's retarding the energy of the object, so thats friction coefficient x normal force x distance, 0.5 x 0.6 x 9.8 x cos20 = 2.76, the distance is one.
then i subtract the total work which is 0.6 x 9.8 x 6sin20 = 12.07 with 2.76 and get 9.31 J. ok, now wut happens? i spent about 3 hours on this problem already, please help!

don't forget part b which i completely don't get at all

[Doc Al]

Try this: As the block slides down the frictionless ramp, energy is conserved. Potential Energy is transformed to Kinetic Energy. So find the KE at the bottom of the ramp. Then, as the block slides along the horizontal surface, it uses up that energy in doing work against friction.

For parts a and b, use ΔKE = Work done by friction on the block

(Also, please don't post the same question multiple times!)