To find average speed, we divide the distance of travel (in this case, 400 metres) by the time she took, 32 seconds. Therefore: 12.5 seconds is her average speed.
Answer:
6621.6 Joule
0.46525
Explanation:
F = Force = 356 N
s = Displacement = 18.6 m
m = Mass of block = 78 kg
Work done

The work done by the horizontal force is 6621.6 Joule

The coefficient of friction between the block and the rough surface is 0.46525
Answer:
The rate of change of an object's velocity is called acceleration.