Question

A force of 100 N acts on a body of mass 1kg at rest. Work done in 4 seconds

Answer 1

Answer:

• Work Done (W) = 80 Kilo Joules.

Given:

1. Force Applied (F) = 100 N.
2. Mass of the Body (M) = 1 Kg.
3. Time taken (t) = 4 Seconds.
4. Initial velocity (u) = 0 m/s.

Explanation:-

$\rule{300}{1.5}$

From Newton's second law of motion,

$\large{\boxed{\bold{F = Ma}}}$

Substituting the values,

$\large{\tt \hookrightarrow 100 \: N = 1 \: Kg \times a}$

$\large{\tt \hookrightarrow 100 = 1 \times a}$

$\large{\tt \hookrightarrow a = \dfrac{100}{1}}$

$\large{\hookrightarrow {\underline{\underline{\tt a = 100 \: m/s^2}}}}$

$\rule{300}{1.5}$

$\rule{300}{1.5}$

From Second kinematic equation,

$\large{\boxed{\bold{S = ut + \dfrac{1}{2}at^2}}}$

Substituting the values,

$\large{\tt \hookrightarrow S = 0 \times 4 + \dfrac{1}{2} \times 100 \times (4)^2}$

$\large{\tt \hookrightarrow S = 0 + \dfrac{1}{2} \times 100 \times (4)^2}$

$\large{\tt \hookrightarrow S = \dfrac{1}{2} \times 100 \times (4)^2}$

$\large{\tt \hookrightarrow S = \dfrac{1}{2} \times 100 \times 16}$

$\large{\tt \hookrightarrow S = \dfrac{1}{\cancel{2}} \times 100 \times \cancel{16}}$

$\large{\tt \hookrightarrow S = 1 \times 100 \times 8}$

$\large{\tt \hookrightarrow S = 1 \times 800}$

$\large{\hookrightarrow {\underline{\underline{\tt S = 800 \: m}}}}$

$\rule{300}{1.5}$

$\rule{300}{1.5}$

Applying Work done formula,

$\large{\boxed{\bold{W = F.s}}}$

Substituting the values,

$\large{\tt \hookrightarrow W = 100 \: N \times 800 \: m}$

$\large{\tt \hookrightarrow W = 100 \times 800}$

$\large{\tt \hookrightarrow W = 80000}$

$\large{\tt \hookrightarrow W = 80 \times 10^{3}}$

$\huge{\boxed{\boxed{\tt W = 80 \: KJ}}}$

∴ Work done is 80 Kilo Joules.

$\rule{300}{1.5}$

Answer 2

◆◆【SOLUTION】◆◆

As we all know that work is some what associated with the dot multiplication of force with displacement.

●【dw = f.dr.cos Ѳ】●

If force is constant than this equation look something like....where Ѳ is the angle between them....

♂♂ W = f.s cosѲ ♂♂

As you do not mention the angle so I assume it to be zero.

Force = mass × Acceleration

100 N = 1kg × Acceleration

【Acceleration=100m/sec²】

ACC TO EQUATION OF MOTION...

S = ut + 1/2at²

S = 0 + 1/2(100)(4)²

S = 50×16

◆【S = 800m】◆

W =f.S

W = 100 × 800

WORK = 8 × 10^4 J

#answerwithquality

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