The effiency of a machine is
(output work or energy) / (input work or energy) .
For the system described in the question, that's
(123 J) / (150 J) = 0.82 = 82% .
Answer:
Inclined planes are simple machines used to make work easier. Ramps, ladders, and staircases are all inclined planes.
Explanation:
First let's find the time it takes for the first ball to land:
Acceleration is a=-g so vertical velocity is V=-gt + V1sin(30).
Position is thus
S=(-1/2)gt^2 +V1t sin(30).
Solving for t gives
t=2V1sin(30)/g
The second ball has the same position function except for the new velocity, which is given by
V2=2V1. Putting this in and solving for t2 gives
t2=4V1sin(30)/g.
It takes twice as long for the second ball to land on the ground.
The horizontal distance of ball 1 is S1 = V1t cos(30). Again we look at ball 2's distance by substituting V2=2V1 and get
S2 = 2V1t2 cos(30).
Note here I put in t2 since it will fly for that amount of time. But we already saw that
t2 = 2t1
So S2=4V1 cos(30)
That is the second ball goes 4 times further than the first one. This is because it is going twice as fast along both the horizontal and the vertical. It moves horizontally twice as fast for twice as long.
The correct answer of this question is : Negative focal length and virtual images.
EXPLANATION:
The concave lens is that transparent spherically refracting surface which is diverging in nature. It is so because it is bulged at the edges and thinner in the centre.
The focal length of the concave lens is always taken negative.
As the lens is diverging in nature, it always forms virtual,erect and diminished image. It means the image formed by concave lens has less size as compared to object.
Hence, the correct answer of this question is that concave lenses have negative focal length and always form virtual images.
The equation for Kc:
Kc = [C]² / [A] [B]
Let the equilibrium concentration of C be x
Then,
the equilibrium concentration of A = 1-x
the equilibrium concentration of B = 1-x
The equation becomes:
4 = x² / (1 - x)²
3x² - 8x + 4 = 0
x = 2, x = 2/3
The first answer is not possible so x = 2/3
[A] = 1 - 2/3 = 1/3
[B] = 1 - 2/3 = 1/3