Efficiency is calculated through dividing the actual mechanical advantage by the hypothetical mechanical advantage:
- the actual mechanical advantage is 9J because that's how much work the light bulb doing
- the hypo. mechanical advantage is 100J. Ideally, in a perfect world, the light bulb can convert 100J input into 100J output, but do to resistance and other factors it is not possible.

change the decimal to a percentage:

the light bulb had 9% efficiency
Answer:
A sound wave is called a longitudinal wave because compressions and rarefactions in the air produce it. The air particles vibrate parallel to the direction of propagation.
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Local winds are driven by temperature differences in areas fairly close to each other. If water and land absorbed and released heat at the same rate, there wouldn't be any temperature differences and nothing to power local winds. See the related link for further information.
Answer:
λ = 623.2 nm
Explanation:
We are given;
separation distance; d = 0.195 mm = 0.195 × 10^(-3) m
interference pattern distance; D = 4.85 m
Width of two adjacent bright interference; w = 1.55 cm = 1.55 × 10^(-2) m
Formula for fringe width is given as;
w = λD/d
Where λ is wavelength
Thus;
λ = dw/D
λ = (0.195 × 10^(-3) × 1.55 × 10^(-2))/4.85
λ = 0.0000006232 m
Converting to nm gives;
λ = 623.2 nm