Answer:
The specific gravity of the unkown liquid is 15.
Explanation:
Gauge pressure, at the bottom of the tank in this case, can be calculated from

where
and
are the height of the column of oil and the unkown liquid, respectively. Writing for
, we have

Relative to water, the unknow liquid specific weight is 15 times bigger, therefore this is its specific gravity as well.
Answer:
A stripe of magnetic information that is affixed to the back of a plastic credit or debit card.
Answer:
Part a)

Part b)
North of East
Explanation:
Speed of train towards East = 60 km/h
displacement towards East is given as

now it turns towards 50 degree East of North
so its distance is given as


then finally it moves towards west for 50 min

Now the total displacement of the train is given as



now total time duration of the motion is given as


now average velocity is given as


Part a)
magnitude of the average velocity is given as



Part b)
Direction of the velocity is given as


North of East
Answer:
a) 600 meters
b) between 0 and 10 seconds, and between 30 and 40 seconds.
c) the average of the magnitude of the velocity function is 15 m/s
Explanation:
a) In order to find the magnitude of the car's displacement in 40 seconds,we need to find the area under the curve (integral of the depicted velocity function) between 0 and 40 seconds. Since the area is that of a trapezoid, we can calculate it directly from geometry:
![Area \,\,Trapezoid=(\left[B+b]\,(H/2)\\displacement= \left[(40-0)+(30-10)\right] \,(20/2)=600\,\,m](https://tex.z-dn.net/?f=Area%20%5C%2C%5C%2CTrapezoid%3D%28%5Cleft%5BB%2Bb%5D%5C%2C%28H%2F2%29%5C%5Cdisplacement%3D%20%5Cleft%5B%2840-0%29%2B%2830-10%29%5Cright%5D%20%5C%2C%2820%2F2%29%3D600%5C%2C%5C%2Cm)
b) The car is accelerating when the velocity is changing, so we see that the velocity is changing (increasing) between 0 and 10 seconds, and we also see the velocity decreasing between 30 and 40 seconds.
Notice that between 10 and 30 seconds the velocity is constant (doesn't change) of magnitude 20 m/s, so in this section of the trip there is NO acceleration.
c) To calculate the average of a function that is changing over time, we do it through calculus, using the formula for average of a function:

Notice that the limits of integration for our case are 0 and 40 seconds, and that we have already calculated the area under the velocity function (the integral) in step a), so the average velocity becomes:

The state of matter that the particles move independently of one another with very little attraction is, I believe, gas