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CBSE Class 11-science Answered

Why a coolie does no work when he moves on a level road while carrying a box on his head?
Asked by Topperlearning User | 04 Jun, 2014, 13:23: PM
answered-by-expert Expert Answer

Work done is given by:

The coolie applies force at right angle to the displacement. Therefore,
Hence,
Answered by | 04 Jun, 2014, 15:23: PM

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CBSE 11-science - Physics
plz elaborate by figure and step by step 1 no. ka question
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Asked by Harshhacker2580 | 04 May, 2020, 17:30: PM
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CBSE 11-science - Physics
What are conservative and non-conservative forces. Give one example of each force.
Asked by Topperlearning User | 09 Jul, 2014, 10:23: AM
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CBSE 11-science - Physics
Why a coolie does no work when he moves on a level road while carrying a box on his head?
Asked by Topperlearning User | 04 Jun, 2014, 13:23: PM
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CBSE 11-science - Physics
Write four properties of conservative forces.
Asked by Topperlearning User | 09 Jul, 2014, 10:26: AM
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CBSE 11-science - Physics
Explain that gravitational force is a conservative force.
Asked by Topperlearning User | 04 Jun, 2014, 13:23: PM
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CBSE 11-science - Physics
Calculate the velocity of the bob of simple pendulum at its mean position if it is able to rise to vertical height of 20 cm. Take g = 9.8 m/s2.
Asked by Topperlearning User | 09 Jul, 2014, 10:29: AM
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CBSE 11-science - Physics
Find the maximum compression in a spring of spring constant 800 N/m, if it is hit by a ball of 0.5 kg released from the height of 10 m. The ball initially followed a curved path and then move horizontally on a frictionless surface to meet the target.
Asked by Topperlearning User | 09 Jul, 2014, 10:33: AM
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CBSE 11-science - Physics
A ball at rest is dropped from a height of 10 m. It loses 25% of its kinetic energy in striking the ground. Find the height to which it bounces. Give the reason of loss of kinetic energy.
Asked by Topperlearning User | 09 Jul, 2014, 10:36: AM
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CBSE 11-science - Physics
A ball of mass 0.1 kg is thrown vertically up with a velocity of 10 m/s. At what height, will its kinetic energy be half its original value?
Asked by Topperlearning User | 09 Jul, 2014, 10:38: AM
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CBSE 11-science - Physics
250 joules were spent in lifting a 10 kg weight to a height of 2 m. Calculate the acceleration with which it was raised. (Take g = 10 m/s2)
Asked by Topperlearning User | 09 Jul, 2014, 10:43: AM
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