Answer:
Explanation:
The package had the same velocity as the plane when it was dropped. Newton's 1st Law says that "an object in motion tends to stay in motion, at the same velocity, in a straight line unless acted on by an outside force".
There only outside force acting on the package was its weight -- that force is straight down. The horizontal velocity that the plane gave the package continued (as Newton said it would), so as it fell, horizontally it kept pace with the plane.
Answer:
90 C
Explanation:
Electric current: This can be defined as the rate of flow of electric charge in a circuit. This can be expressed mathematically as,
I = dQ/dt
dQ = Idt
∫dQ = ∫Idt
Q = It................................ Equation 1
Where Q = amount of charge, I = current, t = time.
Given: I = 3.6 A, t = 25 s.
Substituting into equation 1,
Q = 3.6(25)
Q = 90 C.
Hence the amount of charge passing through the cross section of the conductor = 90 C
Answer:
2f
Explanation:
The formula for the object - image relationship of thin lens is given as;
1/s + 1/s' = 1/f
Where;
s is object distance from lens
s' is the image distance from the lens
f is the focal length of the lens
Total distance of the object and image from the lens is given as;
d = s + s'
We earlier said that; 1/s + 1/s' = 1/f
Making s' the subject, we have;
s' = sf/(s - f)
Since d = s + s'
Thus;
d = s + (sf/(s - f))
Expanding this, we have;
d = s²/(s - f)
The derivative of this with respect to d gives;
d(d(s))/ds = (2s/(s - f)) - s²/(s - f)²
Equating to zero, we have;
(2s/(s - f)) - s²/(s - f)² = 0
(2s/(s - f)) = s²/(s - f)²
Thus;
2s = s²/(s - f)
s² = 2s(s - f)
s² = 2s² - 2sf
2s² - s² = 2sf
s² = 2sf
s = 2f
Answer:
i can't sorry
Explanation:
I didn't really pay attention in that class
First of all, let's just talk about the speed, and not get wound up
in the velocity. OK ?
If a fly is sitting on the rim of the wheel and the wheel is rotating, then for
each full revolution of the wheel, the fly travels the circumference of the
wheel, which is (2 π) x (radius of the wheel).
In 'N' revolutions, the fly travels (2 N π) x (the radius). and so on.
So if the wheel is going, let's say 71 revs per minute (RPM), a point
on the rim is moving at (2 π times 71) x (the radius) per minute.
Another way to say it:
Speed of a point on the circle = (2 π) x (rotation frequency) x (radius).
The 'rotation frequency' takes care of the unit of time, and the 'radius'
takes care of the unit of length, so the result is a speed.
