Friction is a force that holds back the movement of a sliding object. You will find friction everywhere that objects come into contact with each other. The force acts in the opposite direction to the way an object wants to slide.
Answer: The correct answer is option(B.).
Explanation:
The co-formation theory explain that both moon and the earth are formed at same time from the primitive solar nebula (cloud made up of dust and gases) at the same and same place.
Where as capture theory suggests that the moon is an asteroid which was formed or created somewhere else in a solar system. And when the moon approached the earth planet it got captured by the earth's gravitational field.
Impact theory explains the formation of moon by the catastrophic collision between the earth and any planet half the size of earth's size.
Synchronous theory sheds the light on the rotation time, revolution time and sides of moon located from the surface of the earth.
Hence, the correct answer is option(B).
Answer:
c=0.14J/gC
Explanation:
A.
2) The specific heat will be the same because it is a property of the substance and does not depend on the medium.
B.
We can use the expression for heat transmission
In this case the heat given by the metal (which is at a higher temperature) is equal to that gained by the water, that is to say
for water we have to
c = 4.18J / g ° C
replacing we have
I hope this is useful for you
A.
2) El calor específico será igual porque es una propiedad de la sustancia y no depende del medio.
B.
Podemos usar la expresión para la transmisión de calor
En este caso el calor cedido por el metal (que está a mayor temperatura) es igual al ganado por el agua, es decir
para el agua tenemos que
c=4.18J/g°C
reemplazando tenemos
First
let us imagine the projectile launched at initial velocity V and at angle
θ relative to the horizontal. (ignore wind resistance)
Vertical component y:
The
initial vertical velocity is given as Vsinθ
The moment the projectile reaches the maximum
height of h, the vertical velocity
will be 0, therefore the time t taken to attain this maximum height is:
h = Vsinθ - gt
0 = Vsinθ - gt
t = (Vsinθ)/g
where
g is acceleration due to gravity
Horizontal component x:
The initial horizontal velocity is given as Vcosθ. However unlike
the vertical component, this horizontal velocity remains constant because this is unaffected by gravity. The time to travel the
horizontal distance D is twice the value of t times the horizontal velocity.
D = Vcosθ*[(2Vsinθ)/g]
D = (2V²sinθ cosθ)/g
D = (V²sin2θ)/g
In order for D (horizontal distance) to be
maximum, dD/dθ = 0
That is,
2V^2 cos2θ / g = 0
And since 2V^2/g must not be equal to zero, therefore cos(2θ) = 0
This is true when 2θ = π/2 or θ = π/4
Therefore it is now<span> shown that the maximum horizontal travelled is attained when
the launch angle is π/4 radians, or 45°.</span>
