A man is throwing bricks of mass 2 kg onto a roof of height 2 m- Bricks reach the roof with speed 2-10 m-s- Man throws 10 bricks in a minute- If the power of man is W watt- then 3W10 is equal to- take g-10 ms-2

Given the number of bricks =10 t=60 sec m=2 kg, h=2 m v=2√(10) m/sec Work done by man on bricks nbsp; =n(mgh+12mv^2) ∴ P=10(2×10×2+12×2×(2√(10))^2)60 P=403 ...

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Standard XII

Physics

Motion Under Variable Acceleration

A man is thro...

Question

A man is throwing bricks of mass $2 k g$ onto a roof of height $2 m$ . Bricks reach the roof with speed $2 \sqrt{10} m / s$ . Man throws 10 bricks in a minute. If the power of man is $W$ watt, then $\frac{3 W}{10}$ is equal to: (take $g = 10 {ms}^{- 2}$ )

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Solution

Given number of bricks =10
$t = 60 s e c$
$m = 2 k g, h = 2 m v = 2 \sqrt{10} m / s e c$
Work done by man on bricks
$= n (m g h + \frac{1}{2} m v^{2}) ∴ P = \frac{10 ⎛ ⎝ 2 \times 10 \times 2 + \frac{1}{2} \times 2 \times (2 \sqrt{10})^{2} ⎞ ⎠}{60}$

$= \frac{40}{3} w a t t = \frac{40}{3} \times \frac{3}{10} = 4$

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A man is throwing bricks of mass 2 kg onto a roof of height 2 m. Bricks reach the roof with speed 2√10 m/s. Man throws 10 bricks in a minute. If the power of man is W watt, then 3W10 is equal to: (take g=10 ms−2)

Given number of bricks =10 t=60 sec m=2 kg, h=2 mv=2√10 m/sec Work done by man on bricks =n(mgh+12mv2)∴P=10⎛⎝2×10×2+12×2×(2√10)2⎞⎠60 =403 watt=403×310=4

A man is throwing bricks of mass $2 k g$ onto a roof of height $2 m$ . Bricks reach the roof with speed $2 \sqrt{10} m / s$ . Man throws 10 bricks in a minute. If the power of man is $W$ watt, then $\frac{3 W}{10}$ is equal to: (take $g = 10 {ms}^{- 2}$ )