The correct answer is A: H3PO4
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
Answer:
1.6 m/s
Explanation:
First you need to find the momentums of each disc by multiplying their velocities with mass.
disc 1: 7*1= 7 kg m/s
disc 2: 1*9= 9 kg m/s
Second, you need to find the total momentum of the system by adding the momentums of each sphere.
9+7= 16 kg m/s
Because momentum is conserved, this is equal to the momentum of the composite body.
Finally, to find the composite body's velocity, divide its total momentum by its mass. This is because mass*velocity=momentum
16/10=1.6
The velocity of the composite body is 1.6 m/s.
To solve this problem we will apply the concepts related to the Doppler effect. The Doppler effect is the change in the perceived frequency of any wave movement when the emitter, or focus of waves, and the receiver, or observer, move relative to each other. Mathematically it can be described as
Here,
=frequency received by detector
=frequency of wave emitted by source
=velocity of detector
=velocity of source
v=velocity of sound wave
Replacing we have that,
Therefore the frequencty that will hear the passengers is 422Hz
1.) equal volume of different substances have "different" masses.
2.)The more closely packed arrangement the particles of a substance have, "increases" its density.
3.)the SI unit of power is "Watts".
4.)an iron nail sinks in water but floats on " mercury ".
5.)balloons used for advertisements are filled with " helium" gas.
6.)"Conduction" is the primary mode of heat transfer in liquid and gases.
I hope this helps you...
