The angular speed of the minute hand is the ratio between the angle covered and the time taken. The angle covered by the minute hand is
, while the time needed is
, so the angular speed is
And the tangential speed is given by
Answer:
The speed of the water shoot out of the hole is 20 m/s.
(d) is correct option.
Explanation:
Given that,
Height = 20 m
We need to calculate the velocity
Using formula Bernoulli equation
Where,
v₁= initial velocity
v₂=final velocity
h₁=total height
h₂=height of the hole from the base
Put the value into the formula
Hence, The speed of the water shoot out of the hole is 20 m/s.
Answer:
Apparent
The key discovery about Cepheid variable stars that led in the 1920s to the resolution of the question of whether spiral "nebulae" were separate and distant galaxies or part of the Milky Way Galaxy was the direct relationship between the pulsation period and the absolute brightness or luminosity of the Cepheid variables. A measurement of apparent brightness of a variable star could then be used to determine the distance to the "nebula" containing it.
Explanation:
A variable star is a star with changing apparent brightness. The changes can occur over years or in a fraction of seconds. For example the sun whose energy output varies by approximately 0.1 percent of its magnitude, over an 11-year solar cycle. This variable(apparent brightness) can be used to determine how far a variable star is (distance). Therefore, a measurement of apparent brightness of a variable star could then be used to determine the distance to the "nebula" containing it.
Answer:
285 Litre ( 1kg of water occupies 1 Litre )
which is identical to 285 dm^3 ie 285 cubes of length 10 cm
and as there are 10 of these linearly in 1 m then there are 10^3 = 1000 dm^3 in each m^3
giving a volume of 0.285 m^3
Of course if you KNEW that 1m^3 of water has a mass of 1000 kg then you would simply have said that the volume was 285/1000 m^3