B is the answer that I know of.
Answer:
For elliptical orbits: seldom
For circular orbits: always
Explanation:
We start by analzying a circular orbit.
For an object moving in circular orbit, the direction of the acceleration (centripetal acceleration) is always perpendicular to the direction of motion of the object.
Since acceleration has the same direction of the force (according to Newton's second law of motion), this means that the direction of the force (the centripetal force) is always perpendicular to the velocity of the object.
So for a circular orbit,
the direction of the velocity of the satellite is always perpendicular to the net force acting upon the satellite.
Now we analyze an elliptical orbit.
An elliptical orbit correponds to a circular orbit "stretched". This means that there are only 4 points along the orbit in which the acceleration (and therefore, the net force) is perpendicular to the direction of motion (and so, to the velocity) of the satellite. These points are the 4 points corresponding to the intersections between the axes of the ellipse and the orbit itself.
Therefore, for an elliptical orbit,
the direction of the velocity of the satellite is seldom perpendicular to the net force acting upon the satellite.
Answer:
Explanation:
Given,
mass of the bar = 1.1 Kg
length of rod, l = 0.40 m
diameter of the rod, d = 2 cm
frequency, f = 1.5 MHz
time, t = 0.12 ms
wavelength of the shock wave = ?
Speed of the wave =
v = 3333.33 m/s
wavelength of the wave
As the rocket is launched from the ground its height will go on increasing till it stops
So the height of rocket will be maximum when its speed becomes zero
so here we can use energy conservation theory
So it will reach upto height 7.35 m
Theory is a guess that consists of something a group of people believe to be true a hypothesis is an educated guess
