A coconut of mass m falls from the tree through a vertical distance of s and could reach ground with a velocity of v ms -1 due to air resistance. Work done by air resistance is
A
- 
B
– 
mv 2
mv 2
C
mgs
D
mv 2 + 2mgs
Text Solution
Verified by ExpertsThe correct answer is:
A
Work done = Change in K.E.
i.e. W g + W a = 
mv 2
where W g = mgs and W a is the work done by air resistance
∴ ∴ W a = -mgs + 
mv 2
= - 
(- v 2 + 2gs)
= - 
(2gs – v 2 )
Prepare Smarter with CGP Edu
Get practice questions, solutions, and test series in one place.
Write a Review
Share your experience with this question and solution.
Commentary
Send your comment, doubt, correction, or feedback to admin.
Similar Questions
Explore conceptually related problems
A spring 40 mm long is stretched by the application of a force. If 10 N force required to stretch t…
A block of mass M is kept on a platform which is accelerating upward with a constant acceleration a…
Figure shows a particle sliding on a frictionless track which terminates in a straight horizontal s…
A bullet of mass 20 g is found to pass two points 30 m apart in a time interval of 4 second. Calcul…
In a ballistics demonstration, a police officer fires a bullet of mass 50.0 g with speed 200 m s –1…
It is well known that a raindrop or a small pebble falls under the influence of the downward gravit…