Answer:
P = 2 pi R / v period of space station
F / m = v^2 / R centripetal force per unit of mass
So F / m = 4 pi^2 R^2 / (P^2 * R) = 4 pi^2 R / P^2
Also, F / m = 9.8 m/s^2 earth's gravitational attraction
So 9.8 = 4 pi^2 R / P^2 or R = 9.8 P^2 / 4 * pi^2) = 195 m
Or D = 2 R = 390 m the diameter required
Answer:
tectonic plates move in opposite direction
Tectonic plates are not necessarily moving in opposite directions, but if there directions are different they form plate boundaries. If they were moving in the same direction they would become the same plate. The more opposite the direction, the more obvious the fault.
Examples of plate boundaries:
Divergent: moving away from each other - mid-Atlantic ridge
Convergent: moving towards each other - the Himalayas (Indian plate subducting under the Eurasian plate forcing up the mountains)
Transform: sliding laterally along each other - San Andreas fault
add the river's velocity to the boat's velocity
5+ 5 = 10 km/h
Hope this helps!
Velocity is a vector, which includes both magnitude and direction. Negative velocity means that B is travelling in an opposite direction of A.
This situation is a good analogy for a substance with a very high density.
The density of any substance is the mass per unit volume. In this case, the mass confined in the given volume is very high, which is the case for a substance with a high density. The particles in the material are also closely packed.
