Answer:
v = 15.65 m/s
Explanation:
We use conservation of mechanical energy between initial (i) and final (f) states:
Pi + KEi = Pf + KEf
At the top of the cave at the instant the bat starts to fall, there is only potential energy since the bat's velocity is zero.
Pi = m g h = 600 J
and the KEi = 0 J (no velocity)
Knowing the height of the cave's roof (12.8 m) , we can find the mass of the bat:
m = 600 J / (g 12.5) = 4.9 kg
Using conservation of mechanical energy, the final state is:
Pf + KEf = 600 J
with Pf = 0 (just touching the ground)
KEf= 1/2 4.9 (v^2)
and we solve for the velocity:
600 J = 0 + 1/2 4.9 (v^2)
v^2 = 600 * 2 / 4.9 = 244.9
v = 15.65 m/s
Sattelites don't need any fuel to stay in orbit. The applicable law is...."objects in motion tend to stay in motion". Having reached orbital velocity, any such object is essentially "falling" around the earth. Since there is no (or at least very little) friction in the vacuum of space, the object does not slow.... It simply continues.
Sattelites in "low" earth orbit do encounter some friction from the very thin upper atmosphere, and they will eventually "decay".
:)
Force = mass * acceleration = 1500kg * 8m/s²
B. Hand-eye Coordination because it can be used in multiple activities
Answer:
Gallium
Explanation:
Gallium is one such element used as a do/pant in a p-type semiconductor.
A do/pant is an impurity added to a semi-conductor used to alter its properties. Semi-conductors have a wide range of applications. They will conduct heat and electricity only under certain conditions. This property is highly desirable and find a wide application in electronics.
For p-type conductors, they are best do/ped with elements with 3 valence electrons. These are group 3 elements. From the choices, only gallium belongs to this group.
Other elements given are good do/pants for n-type semiconductors. They have 5 valence electrons.
