Lakhmir Singh Solutions Class 9 Physics Solutions for Exercise in Chapter 4 - Work And Energy

Question 67 Exercise

A girl weighing 400 N climbs a vertical ladder. If the value of g be 10 m/s2, the work done by her after climbing 2 m will be:

a) 200 J

b) 800 J

c) 8000 J

d) 2000 J

Answer:

The correct answer is b) 800 J

Video transcript

"hey kids welcome to lido q a video i am vinit your lido tutor glad to bring you this question on your screen a girl weighing 400 newton climbs a vertical leather ladder if the value of g be 10 meter per second square the work done by her after climbing 2 meter will be now work done will be equal to mgh that will be 400 okay sorry now the weight is given to you not the mass right so weight is mass into gravitational force this implies 400 by 10 is equal to mass this implies mass is equal to 40 kg therefore work done is equal to 40 into 10 into 2 that is equal to 800 joules right guys in that easy if you still have it out please leave a comment below do like the video and subscribe to our channel i'll see you in our next video until then bye guys keep practicing keep learning"

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