Answer:
<em>Second option</em>
Explanation:
<u>Linear Momentum</u>
The linear momentum of an object of mass m and speed v is
P=mv
If two or more objects are interacting in the same axis, the total momentum is
Where the speeds must be signed according to a fixed reference
The images show a cart of mass 2m moves to the left with speed v since our reference is positive to the right
The second cart of mass m goes to the right at a speed v
The total momentum before the impact is
The total momentum after the collision is negative, both carts will join and go to the left side
The first option shows both carts with the same momentum before the collision and therefore, zero momentum after. It's not correct as we have already proven
The third option shows the 2m cart has a positive greater momentum than the other one. We have proven the 2m car has negative momentum. This option is not correct either
The fourth option shows the two carts keep separated after the collision, which contradicts the condition of the question regarding "they hook together".
The second option is the correct one because the mass 
has a negative momentum and then the sum of both masses keeps being negative
Density=mass/volume
0.79=53/x
x=67.09
Hope this helps!
Answer:
v₂ = 9 v
Explanation:
For this exercise in fluid mechanics, let's use the continuity equation
v₁ A₁ = v₂ A₂
where v is the velocity of the fluid, A the area of the pipe and the subscripts correspond to two places of interest.
The area of a circle is
A = π R²
let's use the subscript 1 for the starting point and the subscript 2 for the part with the constraint
In this case v₁ = v and the area is
A₁ = π R²
in the second point
A₂= π (R / 3)²
we substitute in the continuity equation
v π R² = v₂ π R² / 9
v = v₂ / 9
v₂ = 9 v
Answer:
c) True. factor four
Explanation:
The energy density of an electromagnetic wave is given by
u = ½ ε₀ E² = B² / 2μ₀
Where ε₀ is the dielectric constant and μ₀ the magnetic permittivity.
Let's apply this equation to the present case
If we double the electro field
E ’= 2 E₀
u’= ½ ε₀ (2E₀)²
u’= ½ ε₀ Eo² 4
u’= 4 u₀
Therefore the energy is multiplied by four
Let's check the answers
a) False
b) False
c) True
d) False
e) False
K.E. = 1/2 m v^2
= 1/2( 254) (3^2)
= 1/2 (254) (9)
= 1143 kg m^2
-------
s^2
Check if it correct
