Question

likh do answer please​ please

Answer 1

Answer:-

a)

Given :-

⟹ Mass (m)= 4000g = 4Kg

⟹ Velocity (v) = 20m/s

To find :-

⟹ Kinetic energy (K.E)

Solution :-

⟹ K.E = 1/2 × mv²

• 1/2 × 4 × 20²
• 1/2 × 4 × 400
• 800 J

∴ Kinetic energy of the body is 800 J.

b)

Given :-

⟹ Mass (m) = 400000g = 400Kg

⟹ Potential energy (P.E) = 8000J

⟹ Acceleration due to gravity (g) = 10m/s²

To find :-

⟹ Height (h)

Solution :-

⟹ P.E = mgh

• 8000 = 400 × 10 × h
• 8000 = 4000h
• h = 8000/4000
• h = 2m

∴ The height through which the body can be lifted is 2m.

c)

• 1 joule of work is said to be done when a force of 1 newton displaces a body through a distance of 1 metre in its own direction.
• The S.I unit of work is joule and C.G.S unit is erg.

Relationship between joule and erg:

⟹ 1 joule = 1 N × 1 m

But 1 N = 10⁵ dyne and 1 m = 10² cm

∴ 1 joule = 10⁵ × 10² cm

• 10⁷ dyne × cm
• 10⁷ erg

∴ 1 joule = 10⁷ erg.

Answer 2

Answer:

ke.

pe.formulas'

Explanation: