Answer:
The introduction of machines to make work done more easier and faster
Distance is 90km,time 1 hr
distance 2 is 82km,time 5 hrs
average speed=total distance travelled/total time taken.
90+82=172/5+1=6
average speed=28.7km over hour
Answer:
Explanation:
Total energy is constant
E = mgh + ½mv² + Fd
At the top of the slide, all energy is potential
E = mgh + 0 + 0
At the bottom of the slide, all potential energy has converted to kinetic and work of friction.
mgh = ½mv² + W
W = mgh - ½mv²
W = 30.0[(9.81)(2.0) - ½6²]
W = 48.6 J