Question

How is the power related to the speed at which a body
can be lifted? How many kilograme will ca man
working with the power of 100 W, be able to lift at
constant speed of Ims- vertically? (9-10m5-3)​

Answer 1

Answer:

Power is the rate of doing work.

$power = \dfrac{work}{time}$

$= > power = \frac{force \times displacement}{time}$

$= > power = force \times \frac{displacement}{time}$

$= > power = force \times velocity$

Calculation:

Let mass be x, gravity be g ,

hence ( x × g ) is the weight or force.

$\therefore \: 100 =( x \times g) \times 1$

$= > 100 = 10x$

$= > x = 10 \: kg$

So final answer is :

$\boxed{ \red{mass = 10 \: kg}}$

Additional information about Power:

• Power is a scalar quantity
• It doesn't have any directions but only magnitude
• It also represents the amount of energy converted or transferred per unit time.

Answer 2

$\huge{\underline{\underline{\red{\mathfrak{AnSwEr :}}}}}$

$\small{\underline{\blue{\sf{Given :}}}}$

• Power (P) = 100 W
• Velocity (v) = 1 m/s

$\rule{200}{1}$

$\small{\underline{\green{\sf{Solution :}}}}$

As we know that :

$\large{\boxed{\sf{Power \: = \: \dfrac{Work}{Time}}}}-----(1)$

And,

$\large {\boxed{\sf{Work \: = \:Force \: \times \: Displacement}}}$

Put this value in (1)

We get,

$\implies {\sf{Power \: = \: \dfrac{Foce \: \times \: Displacement}{Time}}} \\ \\ \implies {\sf{Power \: = \: Force \: \times \: velocity}} \\ \\ {\boxed{\sf{P \: = \: F \: \times \: v}}}$

$\rule{200}{2}$

Use the above relation, And take F = mg

$\implies {\sf{P \: = \: (mg)v}} \\ \\ \implies {\sf{100 \: = \: m(10) \: \times \: 1}} \\ \\ \implies {\sf{100 \: = \: 10m}} \\ \\ \implies {\sf{m \: = \: \dfrac{100}{10}}} \\ \\ \implies {\sf{m \: = \: 10 \: kg}} \\ \\ {\boxed{\sf{Mass \: = \: 10 \: kg}}}$