Advertisements
Advertisements
Question
Advertisements
Solution
APPEARS IN
RELATED QUESTIONS
An object thrown at a certain angle to the ground moves in a curved path and falls back to the ground. The initial and the final points of the path of the object lie on the same horizontal line. What is the work done by the force of gravity on the object?
Explain briefly why the work done by a fielder when he takes a catch in a cricket match is negative.
Work done = Force × ........................................
The moon is revolving around the earth in a circular path. How much work is done by the moon?
Give one example each in which a force does (a) positive work (b) negative work, and (c) zero work.
What is the work done against gravity when a body is moved horizontally along a frictionless surface?
State the energy changes which take place when Water stored in the dam is used to turn turbine in dynamo.
Give an example
Chemical energy changes to heat energy.
A truck driver can load oil drums into the back of the truck by pushing them up a sloping plank, or by lifting them directly. Each drum has a mass of 80 kg, the plank is 3 m long, and the back of the truck is 0.8 m above the ground.
(i) How much force would be needed to lift a drum into the truck directly/without using the plank? (Take g = 10 m/s2)
(ii) How much energy would be required in lifting the drum into the truck without the plank?
(iii) If the force needed to push the drum up the plank is 300 N, why is this less than the answer to part (i)?
(iv) When the truck is loaded, the driver drives off. List the major energy changes that take place in moving the truck.
(v) The driver has to stop at the factory gates. What happens to the kinetic energy of the truck?
