Work and Energy - Notes - Class 9 PDF Download

 Page 1


Work & Energy 
Extra Project 
Page 2


Work & Energy 
Extra Project 
Work 
Work is the transfer of energy. 
 
Work is done on an object when you 
transfer energy to that object. 
Page 3


Work & Energy 
Extra Project 
Work 
Work is the transfer of energy. 
 
Work is done on an object when you 
transfer energy to that object. 
      If a first object is the agent that gives 
energy to a second object, then the first 
object does work on the second object. 
The energy goes from the first object into 
the second object. At first we will say that 
if an object is standing still, and you get it 
moving, then you have put energy into 
that object. 
Page 4


Work & Energy 
Extra Project 
Work 
Work is the transfer of energy. 
 
Work is done on an object when you 
transfer energy to that object. 
      If a first object is the agent that gives 
energy to a second object, then the first 
object does work on the second object. 
The energy goes from the first object into 
the second object. At first we will say that 
if an object is standing still, and you get it 
moving, then you have put energy into 
that object. 
Example 
• a golfer uses a club and gets a stationary golf 
ball moving when he or she hits the ball. The 
club does work on the golf ball as it strikes the 
ball. Energy leaves the club and enters the ball. 
This is a transfer of energy. Thus, we say that 
the club did work on the ball.And, before the ball 
was struck, the golfer did work on the club. The 
club was initially standing still, and the golfer got 
it moving when he or she swung the club. 
Page 5


Work & Energy 
Extra Project 
Work 
Work is the transfer of energy. 
 
Work is done on an object when you 
transfer energy to that object. 
      If a first object is the agent that gives 
energy to a second object, then the first 
object does work on the second object. 
The energy goes from the first object into 
the second object. At first we will say that 
if an object is standing still, and you get it 
moving, then you have put energy into 
that object. 
Example 
• a golfer uses a club and gets a stationary golf 
ball moving when he or she hits the ball. The 
club does work on the golf ball as it strikes the 
ball. Energy leaves the club and enters the ball. 
This is a transfer of energy. Thus, we say that 
the club did work on the ball.And, before the ball 
was struck, the golfer did work on the club. The 
club was initially standing still, and the golfer got 
it moving when he or she swung the club. 
 
 
 
 
 
 
 
 
 
       So, the golfer does work on the club, transferring energy into the 
club, making it move. The club does work on the ball, transferring 
energy into the ball, getting it moving.