a. lowering the sack: negative work.
b. horizontal: no work
c. correct
d. on d, you are doing work against friction, AND adding KE to thecar.
Work=friction*distance+1/2 m (vf^2-vi^2)
Determine the amount of work required for each of the following:
a) to lower a 35kg sack of rice through a height of 3.5m
b) to carry the 30kg sack of rice 10m along a corridor
c)to crave the sack of rice 15m along the corridor at a constant velocity against a frictional force of 88N
d) to accelerate a 1680kg car from 30km/h to 70km/h against a constant force of air resistance of 750N over a distant of 85m.
Sorry for a lot of questions, I'm just struggling to understand work.
I don't really understand the first two at all, would their be no work? And then for c I guess it's 88x15. Then for d it would be 1380x9.8=FN and FG. The ff would equal 750N but I'm not sure how to find the FA from that information
1 answer
1 answer