Answer:
the combination,decomposition or replacement that occurs in the molecules of matter during chemical change called chemical reaction
Mechanical energy = potential energy + kinetic energy
The ball is on the ground so it has no potential energy. that's all i know.
Answer
given,
height of Alpe d'Huez = 1100-m
time = 37.5 min
mass of the rider and his bike = 65 Kg
the metabolic power to ride = 700 W
U = m g y
U = 65 x 9.8 x 1100
U = 700700 J
since efficiency is 25%
b) 
P = 1245.68 W
Let the unknown distance be xmiles
x/39-x/72=11hr
72x-39x/2808=11hr
33x/2808=11
33x= 30888
x=936miles
U can substitue back to check
at speed of 72mph, he would need 936/72=13hrs
at speed of 39mph, he would need 936/39=24hr
the difference is 24-13=11
Answer:
Work done,W= 250J
Displacement , s = 60
We know that, Work done = Force x displacement
i.e , W = Fxs
250 J = F x 60m
F = 250/60
=4.16 N
Hence , 4.16 N of Force is applied on the body.
