Answer:
Dark matter does not affect our view, humans can see through them.
Explanation:
They do not affect our view because we can see right through the (weakly interacting) dark matter, as they do not interact or interfere with electromagnetic force.
Dark matter are often invisible substances and are difficult to spot because they don't absorb or reflect light.
Answer:
a) 3-in. pipe
Explanation:
Given that
Fluid flow is in same amount in the same time it means that volume flow rate is same for the pipes
Volume flow rate
Q = A V
A=Area ,V=Velocity

If diameter d is more then the velocity will be less for same volume flow rate .We also Know that if pressure is more then the velocity will be less.
The second pipe 3 in diameter having more diameter then the velocity will be less but the pressure will be more.
That is why the 3 in diameter is having more pressure than 2 in diameter pipe.
Therefore the answer will be a.
a) 3-in diameter pipe
Answer:
I think the answer is b but i cannot confirm cuz this is a challenging question
Answer:
625 W
Explanation:
Applying
P = W/t.................... Equation 1
Where p = power, W = Work, t = time
But,
W = Force (F) × distance (d)
W = Fd........................ Equation 2
Substitute equation 2 into equation 1
P = Fd/t.................... Equation 3
From the question,
Given: F = 5000 N, d = 30 m, t = 4 munites = (4×60) seconds = 240 seconds
Substitute these values into equation 3
P = (5000×30)/240
P = 625 Watt
Answer:
50 watts
Explanation:
Applying,
Power (P) = Workdone (W)/Time(t)
But,
Work done (W) = Force (F)×distance(d)
Therefore,
P = Fd/t..................... Equation 1
Where P = power of the weightlifter, F = Force applied, d = distance, t = time.
From the question,
Given: F = 200 N, d = 0.5 m, t = 2 s
Substitute these values into equation 1
P = (200×0.5)/2
P = 100/2
P = 50 watts