A force → F = 3 ^ i + 2 ^ j + c ^ k acts on a particle and causes a displacement → r = c ^ i + 4 ^ j + c ^ k meter. The work done is 36 joule.Find the value of 'c' ? Options: A . &nbsp 7 B . &nbsp -7 C . &nbsp 4 D . &nbsp 0

Answer: Option B : B and C → F = 3 ^ i + 2 ^ j + c ^ k → r = c ^ i + 4 ^ j + c ^ k Work = 36j W = → F . → r 36 = ( 3 ^ i + 2 ^ j + c ^ k ) . → F = ( c ^ i + 4 ^ j + c ^ k ) 36 = 3c + 8 + c 2 ⇒ c 2 + 3 c − 28 = 0 (c+7) (c - 4) c = -7 or 4

A force →F=3^i+2^j+c^k acts on a particle and causes a displacement

Discussion Forum : Work Power And Energy

Question -

A force $\to F = 3^i + 2^j + c^k$ acts on a particle and causes a displacement $\to r = c^i + 4^j + c^k$ meter.

The work done is 36 joule.Find the value of 'c' ?

Options:

A . 7

B . -7

C . 4

D . 0

Answer: Option B
:
B and C

$\to F = 3^i + 2^j + c^k$

$\to r = c^i + 4^j + c^k$

Work = 36j

W = $\to F . \to r$

36 = $(3^i + 2^j + c^k) . \to F = (c^i + 4^j + c^k)$

36 = 3c + 8 + $c^{2}$

$\Rightarrow c^{2} + 3 c - 28 = 0$

(c+7) (c - 4)

c = -7 or 4

Was this answer helpful ?

Next Question

Discussion Forum : Work Power And Energy

Submit Your Solution hear: