Answer:
They hold it tightly to their shoulder because the gun recoils and jumps back so by holding it to their shoulder it allows them to stablize the gun so that when it jumps in stead of the gun kicking back and flying the gun jumps and hit the shoulder.
Explanation:
Answer:
electric energy ( power ) = 300000 W
Explanation:
given data
mechanical (hydroelectric) energy = 120 MJ/min = 2000000 J/s
efficiency = 15 % = 0.15
solution
we know that Efficiency of electric engine is expression as
Efficiency = Mechanical energy ÷ electric energy ......................1
and here dam electrical power output is
put here value in equation 1
electric energy ( power ) = Efficiency × Mechanical energy ( power )
electric energy ( power ) = 0.15 × 2000000 J/s
electric energy ( power ) = 300000 W
The equation of the wave travelling along the +x-axis is y = 0.02 sin (880π/330 x – 880 πt)
<u>Explanation:</u>
Given data
Amplitude 0.02 m , Frequency= 440 Hz ,Speed = 330 m/s
The equation format is written as,
y = A sin ( k x – ω t)
We need the value of A, k, x -ω t
<u>1. Find the k value</u>
v = f ×λ
330 = 440×λ
k = 2π×λ
k = 880 π /330 m-1
440 ×2π = w
<u>2. Find the ω value</u>
f×2π =ω
ω
= 880 π s-1
<u>3. Find the A value</u>
we get A value from the given data
A = 0.02 m
By the formula,
y = A sin ( k x – ω t)
Substitute the values we get the equation,
y = 0.02 sin (880π/330 x – 880 πt)
The equation of the wave travelling along the +x-axis is y = 0.02 sin (880π/330 x – 880 πt)
The body of a porter carrying load on head on a level road uses more energy than is required when the porter is resting completely. In this way the porter is doing some work.
However, when we think of theoretical definition of work, there is no force resisting the horizontal movement of the load when carried on a level road, and therefore there is no work done when a porter carrying a load on his head walk along a level road.
When the porter is going down the stairs the gravitational energy acting on the load is assisting the downward movement of the load. In this way energy is released by downward movement of the load. Thus the porter is doing negative work on the load.
