Advertisements
Advertisements
Question
A coolie carrying a load on his head and moving on a frictionless horizontal platform does no work. Explain the reason why.
Solution
We know W = F d cos θ.
Since force is normal to displacement.
So θ = 90°
Hence work done W = Fd cos θ 90 = 0.
APPEARS IN
RELATED QUESTIONS
A coolie X Carrying a load on his head climbs up a slope and another coolie Y carrying the identical load on his head move the same distance on a frictionless horizontal platform. Who does more work? Explain the reason.
Name the quality which is measured in eV
State the condition when a force produces
(i) linear motion.
(ii) rotational motion, in a body.
What is the work done when the force on the object and the displacement of the object are perpendicular to each other?
An engine does 54,000 J of work by exerting a force of 6000 N on it. What is the displacement in the direction of the force?
In the following case write yes, if the work is being done and no if no work is being done.
A man moving on the rough ground.
State the condition when the work done by the force is positive
A force F when acts on a body, displace it by a distance d in a direction at an angle θ with the direction of the force. Write down the expression for the work done by the force.
Calculate the work done when:
A car is moved on a rough road through 30 m against a frictional resistance of 75 N.
A coolie carries a load of 30 kgf through a distance of 500 m in 5 minutes while another coolie B carries the same load through the same distance in 10 minutes. Compare the
(i) work done, and
(ii) power developed. (Take: g = 10md−2)
