Answer:
Explanation:
radius of cylinder r₁ = .02 m
radius of safety valve r₂ = .0075 m
force exerted by spring on safety valve = 950 x .0085 = 8.075 N .
Force required on piston of cylinder = F
Applying Pascal's law
8.075 / 3.14 x .0075² = F / 3.14 x .02²
F = 8.075 x .02² / .0075²
= 8.075 x 7.111
= 57.42 N .
Answer:
It will take 2.45 seconds.
Explanation:
A football field measured 120 yards, that is arround 0.068 miles, the car is moving with a constant speed so the formula we have to apply for this is:
in order to obtain the time in seconds:
The answer is the Milky Way .
Answer is D.
Speed:
Use relative speed to simplify the situation. Since the trains are moving in opposite directions, you can add the speeds and pretend the first train is stationary (moving at 0m/s) and the second train is moving at 50m/s.
Distance:
The front of the second train needs to travel 120m to get from the front to the back of the first train. When the front of the second train is at the back of the first train, the back of the second train is still 10m in front of the first train. The back therefore has to travel 130m to clear the first train. The total distance over which the trains are overlapping in this scenario is therefore 120 + 130 = 250m.
You have speed and you have distance so now just calculate time:
v = d / t
50 = 250 / t
t = 5s
Answer: A
The diffusion time through the edge is double the diffusion time through the center.
Explanation:
Only the diffusion coefficient, thickness, surface area, distance affects the time it takes a gas such as oxygen to diffuse a given in a medium. The Diffusion time increases with the square of diffusion distance Also, the Increased surface area increases the rate of diffusion or the diffusion time, whereas a thicker membrane reduces the rate of diffusion or time it takes the gas to be permeable. Also, The greater the distance that a substance must travel, the slower the rate of diffusion The diffusion coefficient determines the time it takes a gas to diffuse. Also the Diffusion time is inversely proportional to the diffusion coefficient.
Now, If the edge of a contact lens is double the thickness of the central portion of the lens, then it will take more time for the gas to diffuse through the thicker portion. since its edge is double the central position, then the diffusion time will also be doubled. So Option A is the best answer-
The diffusion time through the edge is double the diffusion time through the center.
