Answer:
I think it is the forth one
Answer:
$4.2
Explanation:
Given data
Power= 700W
time= 10 hours
Cost per kilowatt hours is cents $0.20
Let us find the number of hours in a month
=24*30
=720 hours
Energ= power*time
Energy= 700/1000*30
Energy= 7*3
Enery= 21 kwh
1 kwh= 0.2
21kwh= x
cross multiply
x=21*0.2
x= $4.2
The energy bar eaten by Sheila has chemical energy locked up inside it. This chemical energy is converted to mechanical energy in form of potential and kinetic energy and this in turn is converted to heat energy as the run progresses. Thus, the energy changes are: chemical energy to mechanical energy [kinetic and potential] and finally to heat energy.
Since static friction is the minimum force required to just start the motion of a stationary object.
Here if we need to start an object from rest then we required F = 700 N
So for the first part of the above problem Force will be F = 700 N
Now if the box is already moving then we will have to use kinetic friction force between box and floor
now we can write the equation of net force as
here
now we will have
