Question

Calculate the work done to raise a granite plate 0.5m³ in volume to height 20m. The density of granite is 2500 kg/m³.​

Answer 1

Answer :-

Work done = 245 kJ

Explanation :-

Analyzing the question,

Given:

• Volume of granite plate = 0.5 m³
• Height = 20 m
• Density of granite plate = 2500 kg/m³

To find:

Work done = ?

Solution:

Here,

Work done = Gravitational potential energy.

Gravitational Potential energy = mgh

where:

• m is the mass of the object
• g is the acceleration due to gravity
• h is the height.

For finding the mass:

Mass = Density × Volume

⇒ Mass = 2500 × 0.5

⇒ Mass = 1250 kg

Applying the above formula of Gravitational potential energy,

Gravitational Potential energy = mgh

⇒ Gravitational Potential energy = 1250 × 9.8 × 20

⇒ Gravitational Potential energy = 245000 J

⇒ Gravitational Potential energy = 245 kJ

∴ Work done = 245 kJ

Answer 2

Answer:

250kj

Explanation:

w=fs

= mg×h

=2500kg/M3 ×0.5m3 ×10m×20 m

= 2500 kg ×5×20 M2/s2

=2500 × 100

250000

250kj