The options are;
a. V2 equals 2V1.
b. V2 equals (V1)/2.
c. V2 equals V1.
d. V2 equals (V1)/4.
e. V2 equals 4V1.
Answer:
Option A: V2 equals 2V1
Explanation:
Since the flow is steady, then we can say;
mass flow rate at input = mass flow rate at output.
Formula for mass flow rate is;
m' = ρVA
Thus;
At input;
m'1 = ρ1•V1•A1
At output;
m'2 = ρ2•V2•A2
So, m'1 = m'2
Now, we are told that the density of the fluid decreases to half its initial value.
Thus; ρ2 = (ρ1)/2
Since m'1 = m'2, then;
ρ1•V1•A1 = (ρ1)/2•V2•A2
Now, the pipe is uniform and thus the cross section doesn't change. Thus;
A1 = A2
We now have;
ρ1•V1•A1 = (ρ1)/2•V2•A1
A1 and ρ1 will cancel out to give;
V1 = (V2)/2
Thus, V2 = 2V1
the answer is d it reflects all the wavelengths of visible light.
Answer:
284.8 kgm/s
Explanation:
Impulse: This can be defined as the product of force and time of a body. The S.I unit of impulse is N.s mathematically.
Impulse = Force × time
Change in momentum: This is the product of the mass of a body and its change in velocity. The unit of change in momentum is kgm/s.
Mathematically,
momentum = mass×change in velocity
Deduction from newton's second law of motion,
Impulse = change in momentum
Therefore,
Change in Momentum = Force×time
ΔM = F×t................. Equation 1
Where F = force = 89 N, t =time = 3.2 s.
Substitute into equation 1
ΔM = 89×3.2
ΔM = 284.8 kgm/s
Thus the change in momentum = 284.8 kgm/s
Evaporation occurs when atoms/molecules leave the surface of the liquid.
Boiling occurs when this evaporation take a place in a body of the liquid.
Answer:
The answer should be 36 Joules.
Explanation:
This can be solved as a angular motion.
Angular velocity w = V/r
Where V is the linear velocity 6 m/s
And r is the radius of rotation which is equal to the lenght of the string 0.8 m
w = V/r = 6/0.8 = 7.5 rad/s
Moment of inertia of rotation I = mr^2
Where m is the mass of the ball 2 kg
I = 2 x 0.8^2 = 1.28 kg-m2
From energy conservation, work done is equal to the kinetic energy of the angular motion.
KE = 0.5Iw^2
= 0.5 x 1.28 x 7.5^2 = 36 Joules.
