When a parallel beam of light passes through a convex lens, the rays become farther from one another when the come out. This process of rays is called ''to diverge''. The concave lens makes rays of light diverge, so it is called diverging lens.
A cooling fan is turned off when it is running at 850 rev/min. It turns 1500 revolutions before it comes to a stop. (a) What was
1 answer:
Answer
given,
cooling fan revolution = 850 rev/min
fan turns before revolution = 1500 revolutions
θ = 1500 revolution
θ = 1500 x 2 x π
θ = 9424.78 rad
a) using equation of rotation
ω² = ω₀² + 2 α θ
ω = 0 because body comes to rest
0 = 89² + 2 x α x 9424.78
α = -0.42 rad/s²
b) time take for the fan to stop
ω = ω₀ + α t
0 = 89 - 0.42 t
t = 211.9 s
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Answer:
Explanation:
fundamental frequency, f = 250 Hz
Let T be the tension in the string and length of the string is l ans m be the mass of the string initially.
the formula for the frequency is given by
.... (1)
Now the length is doubled ans the tension is four times but the mass remains same.
let the frequency is f'
.... (2)
Divide equation (2) by equation (1)
f' = √2 x f
f' = 1.414 x 250
f' = 353.5 Hz
Answer:
Reduce its weight
Explanation:
For an object on a flat surface, the maximum force of friction experienced by the object is given by:
where
is the coefficient of friction
W is the weight of the object
As we can see from the formula, there are two ways of reducing the friction:
- Decreasing --> this coefficient depends on the material and on the roughness of the surface, so this can be changed by changing the properties of the surface
- Decreasing W, the weight --> this can be done by reducing the mass of the object