The true answer is the choice A
Scientists <span>can predict volcanic eruptions as long as adequate resources are available.Volcanic eruptions are one of the earthly activities which can be predicted by means of adequate resources (w</span><span>arming of the earth's crust, appearance of volcanic lava etc...). By contrast, earthquakes is a dangerous natural </span>disaster<span> that scientists cannot be predicted or mastering the time where it occurs.</span>
Answer:
a) Fi = 85.76 N
b) Fi = 87.8 N
Explanation:
Given:-
- Density of hydraulic oil, ρ = 804 kg/m^3
- The radius of input piston, ri = 0.00861 m
- The radius of output piston, ro = 0.141 m
Find:-
What input force F is needed to support the 23000-N combined weight of a car and the output plunger, when
(a) the bottom surfaces of the piston and plunger are at the same level
(b) the bottom surface of the output plunger is 1.10 m above that of the input plunger?
Solution:-
For part a.
- We see that both plungers are equal levels or there is no pressure due to elevation head. So we are only dealing with static pressure exerted by the hydraulic oil on both plungers to be equal. This part is an application of Pascal's Law:
Pi = Po
Fi / Ai = Fo / Ao
Fi = Ai / Ao * Fo
Fi = (ri/ro)^2 * Fo
Fi = ( 0.00861 / 0.141 )^2 * 23000
Fi = 85.76 N
For part b.
- We see that both plungers are at different levels so there is pressure due to elevation head. So we are only dealing with static pressure exerted by the hydraulic oil on both plungers plus the differential in heads. This part is an application of Bernoulli's Equation:
Pi = Po + ρ*g*h
Where, h = Elevation head = 1.10m
Fi = (ri/ro)^2 * Fo + ρ*g*h*π*ri^2
Fi = 85.76 + (804*9.81*1.1*3.142*0.00861^2)
Fi = 87.8 N
TRUE
They propagate perpendicular to each other in the case of an Electromagnetic waves....
Both can be seen in the case of a moving charge
Hope this helps!
Answer:
µ>=0.526.
Explanation:
The friction force is opposite to the horizontal force applied and is given by:
The force applied horizontally need to be bigger so the box can be moved, but in this case, the force friction is bigger so:
So the coefficient of static friction is bigger or equal to 0.526.
Answer:
V = 52
Explanation:
Plug in the numbers:
If v = u + at
it is...
v = 24 + 7(4) = 24 + 28 = 52
