M2 work/energy type question

A block of wood of mass 2kg is pushed across a rough horizontal floor. The block moves at 3m/s and the coefficient of friction is 0.55. Calculate the work done in 2 sec.

So far I know that the friction force is μR = 0.55*2*9.8=10.78N.
Also the distance travelled s=ut so 3m/s*2s=5m. I got no clue of how to use this information to find the actual force to work out the energy. I was thinking of doing f=ma so like
Σf=ma
F-10.78=ma...

I'm so stuck

Posted from TSR Mobile

Reply 1

brianeverit

9

Original post by bigboateng

A block of wood of mass 2kg is pushed across a rough horizontal floor. The block moves at 3m/s and the coefficient of friction is 0.55. Calculate the work done in 2 sec.

So far I know that the friction force is μR = 0.55*2*9.8=10.78N.
Also the distance travelled s=ut so 3m/s*2s=5m. I got no clue of how to use this information to find the actual force to work out the energy. I was thinking of doing f=ma so like
Σf=ma
F-10.78=ma...

I'm so stuck

Posted from TSR Mobile

3 times 2=6 NOT 5.
Work done against friction=friction force times distance moved.