The strength of the gravitational field is given by:

where
G is the gravitational constant
M is the Earth's mass
r is the distance measured from the centre of the planet.
In our problem, we are located at 300 km above the surface. Since the Earth radius is R=6370 km, the distance from the Earth's center is:

And now we can use the previous equation to calculate the field strength at that altitude:

And we can see this value is a bit less than the gravitational strength at the surface, which is

.
T=2s
g=10m/s2
h=?
free fall: h=gt2/2
h= 10*4/2
h=40/2
h=20m
Evaporation (or another word to use is water vapor.)
Answer:
The answer is A
Explanation:
When a rockets thrusters push on the ground the ground pushes back on the rocket with equal force in the opposite direction. Hence the rocket takes off.
Newtons third law of motion states, for every action there is an equal and opposite reaction.
Answer:
Explanation:
<u>Instant Velocity and Acceleration
</u>
Give the position of an object as a function of time y(x), the instant velocity can be obtained by

Where y'(x) is the first derivative of y respect to time x. The instant acceleration is given by

We are given the function for y

Note we have changed the last term to be quadratic, so the question has more sense.
The velocity is

And the acceleration is
