Question

it takes 20 seconds for a person a of mass 50 kg to climb up the stairs while another person be of the same much does the same in 15 seconds compare the work done and the power developed by the persons a and b ​

Answer 1

Answer:

For case of A,

Mass = 50kg

time = 20s

Displacement = d

acceleration = g

{we are taking Acceleration die to gravity cause they are climbing stairs}

Work done = Force × displacement

=> mass × acceleration × displacement

=> 50gd

Power = Work/time

=> 50gd/20

For Case of B,

Mass = 50kg

time = 15 seconds

acceleration = g

displacement = d

{g and displacement will remain the same for B too}

Similarly,

Work done = 50ad

Power = 50gd/15

Ratio of work done by A and B = 50gd/50gd = 1:1

Therefore Work done = 1:1

Ratio of their powers =

20/15

4:3

Ratio of their powers = 4:3

Cheers!For case of A,

Mass = 50kg

time = 20s

Displacement = d

acceleration = g

{we are taking Acceleration die to gravity cause they are climbing stairs}

Work done = Force × displacement

=> mass × acceleration × displacement

=> 50gd

Power = Work/time

=> 50gd/20

For Case of B,

Mass = 50kg

time = 15 seconds

acceleration = g

displacement = d

{g and displacement will remain the same for B too}

Similarly,

Work done = 50ad

Power = 50gd/15

Ratio of work done by A and B = 50gd/50gd = 1:1

Therefore Work done = 1:1

Ratio of their powers =

20/15

4:3

Ratio of their powers = 4:3

Cheers!

Explanation:

Answer 2

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$\huge\bold\red{\underline{\underline{{Question:}}}}$

• It takes 20 seconds for a person A of mass 50 kg to climb up the stairs while another person be of the same much does the same in 15 seconds compare the work done and the power developed by the persons A and B.

$\huge\bold\red{\underline{\underline{{Answer:}}}}$

$\large\bold\blue{\underline{\underline{{Solution:-}}}}$

• In this case,

• For A :-

• Mass = 50 kg

• Time = 20 seconds.

• Displacement = d

• Acceleration = g

(Here, Acceleration die to gravity because they are climbing stairs)

${\boxed{{\bf{Work\:done = Force × displacement}}}}$

$\sf\large\pink{⇝Mass×Acceleration ×displacement }$

$\sf\large\pink{⇝50 gd}$

${\boxed{{\bf{Power = work/time}}}}$

$\sf\large\pink{⇝50gd/20}$

• For B :-

• Mass = 50 kg

• Time = 15 seconds

• Acceleration = g

• Displacement = d

(g and d are same for b too)

• Similarly,

$\sf\large\pink{⇝work\:done = 50ad}$

$\sf\large\pink{⇝Power = 50gd/15}$

• Ratio of work done by A and B = 50gd/50gd = 1:1

• Therefore, work done = 1:1

$\sf\large\pink{⇝Ratio\:of\:their\:powers = \frac{ \frac{50gd}{15} }{ \frac{50gd}{20} } }$

$\sf\large\pink{⇝20/15}$

$\sf\large\pink{⇝4:3}$

• Ratio of their powers = 4:3

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