Question

A person is lowering a bucket full of water (by using an ideal rope) with an acceleration 9.8m/s² through a
distance of 2m. The total mass of water plus bucket system is 10kg. Find the work done by the person on
water plus bucket system. [g = 9.8 m/s²] neglect air resistance

1) –196J
2) +196J
3) –98J
4) Zero​

Answer 1

Answer:

• (2) +196 J is the required answer.

Explanation:

Given:-

• Height ,h = 2m
• Mass ,m = 10 kg
• Acceleration due to gravity ,g = 9.8m/s²

To Find:-

• Work done ,W

Solution:-

As we have to calculate the Work done by persons in against gravity.

As we know that Work Done is calculated by the Product of Force (mg) & displacemet . Here, the person lift the bucket from well . so , the work done by him .

• W = mgh

where,

• W denote Work Done
• m denote mass
• g denote acceleration due to gravity
• h denote height

Substitute the value we get

→ W = 10×9.8×2

→ W = 98×2

→ W = 196 J

• Hence, the work done by the person is 196 Joules.

Options (2) 196 Joules is the required Answer.

Answer 2

Answer:

Given :-

• Acceleration = 9.8 m/s²
• Distance = 2 m
• Acceleration due to gravity = 9.8 m/s
• Mass = 10 kg

To Find :-

Work Done

Solution :-

As we know that

$\bf \red{Work \: Done = mgh }$

• M is the Mass
• G is the Acceleration due to gravity
• H is the Height

$\sf \implies \: Work \: Done = 10 \times 9.8 \times 2$

$\sf \implies \: Work \: Done = 20 \times 9.8$

$\sf \implies \: Work \: Done \: = 2 \times 98$

$\frak \pink{Work \: Done = 196 \: J}$

Hence :-

Option B is correct.