Energy is released or absorbed ,but no loss in total molecules,each of which consists of one atom of oxygen and two of hydrogen,are broken down.!
Some examples of when friction is helpful are: to help the movement of tires. When you walk, and also, when you erase. :)
Answer:
Radius of the circle will be 2.5 m
Explanation:
We have given velocity of particle moving in the circle v = 5 m/sec
Acceleration of particle in the circle 
We have to find the radius of the circle
We know that acceleration is given by 
So 
So radius of the circle will be 2.5 m
Answer:
The manufacturer of a 9V dry-cell flashlight battery says that the battery will deliver 20 mA for 80 continuous hours. During that time the voltage will drop from 9V to 6V. Assume the drop in voltage is linear with time. How much energy does the battery deliver in this 80 h interval?
Explanation:
If F =m*a
and the question says how much force the s needed to accelerate a 68kg skier to a rate of 1.2ms^-2
Then F = 68*1.2
