Heated air rises while cooled air sinks.
To calcculate the braking force of the car moving, we use Newton's second law of motion which relates the acceleration and the force of an object moving. The force of an object moving is directly proportional to its acceleration and the proportionality constant is the mass of the object. It is expressed as:
Force = ma
Acceleration is the rate of change of the velocity of a moving object. We calculate acceleration from the velocity and the time given above.
a = (10 m/s) / 5 s = 2 m/s^2
So,
Force = ma
Force = 1000 kg ( 2 m/s^2 )
Force = 2000 kg m/s^2 or 2000 N
The correct answer is
c) Neither person is correct because light does not change frequency when it travels through different media
In fact, light changes both wavelength and speed when it travels through different media, but the frequency remains the same.
(a) 764.4 N
The weight of the astronaut on Earth is given by:
where
m is the astronaut's mass
g is the acceleration due to gravity
Here we have
m = 78.0 kg
g = 9.8 m/s^2 at the Earth's surface
So the weight of the astronaut is
(b) 21.1 N
The spacecraft is located at a distance of
from the center of Earth.
The acceleration due to gravity at a generic distance r from the Earth's center is
where G is the gravitational constant and M is the Earth's mass.
We know that at a distance of r = R (at the Earth's surface) the value of g is 9.8 m/s^2, so we can write:
(1)
the acceleration due to gravity at r=6R instead will be
And substituting (1) into this formula,
So the weight of the astronaut at the spacecratf location is
