
Actually Welcome to the Concept of the kinematics of a body.
Since, we know that Velocity = Distance / time
hence, V = 20/5 = 4 m/s
hence the velocity of the RC car is 4 m/s westwards direction.
Here is the full question
Suppose there are 10,000 civilizations in the Milky Way Galaxy. If the civilizations were randomly distributed throughout the disk of the galaxy, about how far (on average) would it be to the nearest civilization?
(Hint: Start by finding the area of the Milky Way's disk, assuming that it is circular and 100,000 light-years in diameter. Then find the average area per civilization, and use the distance across this area to estimate the distance between civilizations.)
Answer:
1000 light-years (ly)
Explanation:
If we go by the hint; The area of the disk can be expressed as:

where D = 100, 000 ly
Let's divide the Area by the number of civilization; if we do that ; we will be able to get 'n' disk that is randomly distributed; so ;

The distance between each disk is further calculated by finding the radius of the density which is shown as follows:



replacing d =
in the equation above; we have:




The distance (s) between each civilization = 
= 2 (500 ly)
= 1000 light-years (ly)
Q: The small piston of a hydraulic lift has a cross-sectional of 3.00 cm2 and its large piston has a cross-sectional area of 200 cm2. What downward force of magnitude must be applied to the small piston for the lift to raise a load whose weight is Fg = 15.0 kN?
Answer:
225 N
Explanation:
From Pascal's principle,
F/A = f/a ...................... Equation 1
Where F = Force exerted on the larger piston, f = force applied to the smaller piston, A = cross sectional area of the larger piston, a = cross sectional area of the smaller piston.
Making f the subject of the equation,
f = F(a)/A ..................... Equation 2
Given: F = 15.0 kN = 15000 N, A = 200 cm², a = 3.00 cm².
Substituting into equation 2
f = 15000(3/200)
f = 225 N.
Hence the downward force that must be applied to small piston = 225 N
Answer:
La aceleración necesaria para detener el avión es - 10.42 m/s².
Explanation:
Un movimiento uniformemente acelerado (M.U.A) es aquél cuya aceleración es constante y la velocidad de un objeto cambia a medida que el movimiento evoluciona.
Siendo la aceleración "a" el cambio de velocidad al tiempo transcurrido en un punto A a B, la velocidad inicial la velocidad que tiene un cuerpo al iniciar su movimiento en un período de tiempo y la velocidad final la velocidad que tiene un cuerpo al finalizar su movimiento en un período de tiempo, entonces en M.U.A se cumple:
Vf² - Vo² = 2*a*d
donde:
- Vf: Velocidad final
- Vo: Velocidad inicial
- a: Aceleración
- d: Distancia recorrida
En este caso:
- Vf: 0 m/s, porque el avión se detiene
- Vo: 50 m/s
- a: ?
- d: 120 m
Reemplazando:
(0 m/s)² - (50 m/s)² = 2*a*120 m
Resolviendo:

a= - 10.42 m/s²
<u><em>La aceleración necesaria para detener el avión es - 10.42 m/s².</em></u>
Answer:
the speed of the center of mass stays the same
Explanation:
In a system with no energy loss, momentum is conserved if the mass remains constant. The system described has no change in mass, and energy loss is considered negligible. Hence the product of the total mass and the velocity of its center will be a constant. The center of mass stays the same speed.