Convection is the movement<span> of groups of molecules within </span>fluids<span> such as gases and liquids, including molten rock (rheid).</span>
Answer:
A) The crossbeam is moving relative to the observer on the platform so the height appears contracted.
Explanation:
The observer on the train and the beam are in the same reference frame. That means observer on the train will measure the proper length of the beam not the contracted length . the observer is outside and the plank is in the moving system,it will appear to be moving.
Answer:The locomotor skills include: walking, running, skipping, galloping, hopping, jumping, sliding, walking backwards, and leaping. Students are learning these skills at it could take lots of practice to develop the skills necessary to complete all of the locomotor skills.
Explanation:
Answer:
W = 145.8 [N]
Explanation:
To solve this problem we must remember that weight is defined as the product of mass by gravity, in this case lunar gravity.
W = m*g
where:
m = mass = 90 [kg]
g = gravity acceleration = 1.62 [kg/m²]
W = 90*1.62
W = 145.8 [N]
A. 
The orbital speed of the clumps of matter around the black hole is equal to the ratio between the circumference of the orbit and the period of revolution:

where we have:
is the orbital speed
r is the orbital radius
is the orbital period
Solving for r, we find the distance of the clumps of matter from the centre of the black hole:

B. 
The gravitational force between the black hole and the clumps of matter provides the centripetal force that keeps the matter in circular motion:

where
m is the mass of the clumps of matter
G is the gravitational constant
M is the mass of the black hole
Solving the formula for M, we find the mass of the black hole:

and considering the value of the solar mass

the mass of the black hole as a multiple of our sun's mass is

C. 
The radius of the event horizon is equal to the Schwarzschild radius of the black hole, which is given by

where M is the mass of the black hole and c is the speed of light.
Substituting numbers into the formula, we find
