Answer:
v = 4.4 m / s
Explanation:
Unfortunately, the exercise scheme does not appear. Let's analyze the problem the marble leaves point A with an initial velocity, goes down and then rises to a given height where its velocity is zero, in the whole trajectory they tell us that the resistance is zero, so we can use the conservation relations of the enegy.
Starting point. Point A
Em₀ = K + U = ½ m v2 + mg y_a
point B.
Em_f = U = m g y
the energy is conserved
Em₀ = Em_f
½ m v² + mg y_a = m g y
½ m v² = m g (y -y_a)
v = 
In the exercise the diagram is not seen, but the height of point A must be known, suppose that y_a = 4 m
v = 
v = 4.4 m / s
Answer:
After the colision, the stationary electron's momentum is given as:
P = 2.7328 x 10^(-25) kg m/s
The direction of momentum is the same as the direction of velocity of the electron.
Explanation:
In an Isolated system, when an object moving at some velocity v collides head on with a stationary object of equal mass. There velocities are exchanged.
This means that the first electron will become stationary and the electron which was stationary initially will start moving at a velocity of 3*10^(5)m/s in the same direction as the first electron.
Post collision momentum of the stationary electron:
V = 3 x 10^5 m/s
m = 9.1093 x 10^(-31) kg
Momentum = P = mV = 9.1093 x 10^(-31) x 3 x 10^5
P = 2.7328 x 10^(-25) kg m/s
The direction of momentum is the same as the velocity of the electron.
Answer: D
sleep terror disorder
Explanation:
It is a sleeping disorder causing feelings of panic or dread which typically occur during the first hours of stage 3–4 non-rapid eye movement (NREM) sleep.
Planets are not hot enough, and that's because they lack the internal energy sources that stars have: thermonuclear fusion (They do emit a little light, mainly infrared light, but nothing compared to the sun)
Planets don't have their own light, so simply they do not emit light, this phenomena goes back to their information. When they are formed, they are much, much less hotter than the stars. In stars, fusion reaction always goes on, in which energy, as well as light is formed, so, there is light for stars to emit for a long time.
