Question

I have a doubt can anyone solve this​

Answer 1

Answer:

5 watt

Explanation:

work done = F . S

= (5i + 4j). ( 3i + 4k) = 5 * 3 + 4 * 0 + 0 * 4 = 15 joule

power = work done/time taken

= 15/3 joule per second = 5 watt

Answer 2

$\boxed{\bf{ \red{\bigstar Question \longrightarrow }}}$

A force F= (5i +4j)N displaces a body through S= (3i + 4k)m in 3 sec. Find the power.

$\boxed{\bf{ \blue{\bigstar Find \longrightarrow }}}$

• Power ??

$\boxed{\bf{ \orange{\bigstar Given \longrightarrow }}}$

• $\sf{Force [F]= (5 \hat i + 4 \hat j ) N }$

$\sf{distance[S] = 3 \hat i + 2 \hat k }$

$\boxed{\bf{ \green{\bigstar formulas \ used \longrightarrow }}}$

• $\sf{ P= \dfrac{W}{t} }$
• $\sf{W= F.S}$

where,

P= Power,

W= Work done,

t= Time,

F= Force,

S= Distance.

$\boxed{\bf{ \purple{\bigstar SoLution \longrightarrow }}}$

firstly we will find the W {work done]

$\sf{W= F.S}$

put value in the formula we get,

$\sf{W= (5\hat i + 4\hat j + 0 \hat k) + (3\hat i+0\hat j+4\hat k)}$

$\sf{W= ( 5 \times 3) + (4\times 0) + (0 \times 4 )}$

W= 15J

now we will find the value of power,

$\sf{ P= \dfrac{W}{t} }$

put value of w and t in the formula we get,

$\sf{ P = \dfrac{ 15}{3} = 5 }$

$\boxed{\sf{ P = 5 watt }}$

$\bf{\underline{\pink{\bigstar \therefore Power \ is \ 5 watt. \bigstar }}}$

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