Question

A particle of mass 2 kg travels along a straight line
with velocity v = a underootx, where a is a constant. The
work done by net force during the displacement of
particle from x = 0 to x = 4 m is
(1) a*2
(2) 2a*2
(3) 4a*2
(4) underoot2 a*2​

Answer 1

Answer:

ANSWER

Given, mass=2kg,velocity=a

x

Since, v=a

x

,v=a

4

So, V

2

=u

2

+2as⇒v

2

−u

2

=2as⇒v

2

=2as→a=

2s

v

2

Since, u=0

a=

2s

2a

2

=

4r

2

4a

2

⇒a=

2

a

2

So, workdone =f×ds=2×

2

a

2

×4=4a

2

Answer 2

Answer: $4a^{2}$

Explanation:

$v=a\sqrt{x}$,

m=2 kg

displacement, s=2-0=2m

Let acceleration is a'

At t=0, u=0

We know that $v^{2}+u^{2}=2as$

here, $(a\sqrt{x)} ^{2} +(0)^{2}=2a'*4$

or,$xa^{2}=8a'$

or, $a'=\frac{xa^{2} }{8}$

or, $a'=\frac{4a^{2} }{8}$

or, $a'=\frac{a^{2} }{2}$

now, work done,w=F.s=ma.s=2*a'*4=$8*\frac{a^{2} }{2}$=$4a^{2}$