Answer:
The value of Q is - 8 C
Explanation:
Given;
the magnitude of first charge = 2 C
position of the first charge = 0
_ (2m) 0(+2C) +(2m)(Q)
------------------------------------------------------------------------------------
E₁ --------------------------------->
<------------------------------------------------------------------ E₂
E₁ and E₂ are equal in magnitude but opposite in direction
| E₂ | = | E₁ |

Thus, since E₂ is opposite in direction to E₁, the Q = - 8 C
Answer:
23.38 years
Explanation:
Speed of Allison = 0.83 c = v
Time passed according to Allison = Δt = 29.5 years
Time dilation

For Nora 52.88 years would have passed
So, their age difference would be 52.88-29.5 = 23.38 years
Answer:
370.6 nm
Explanation:
wavelength in vacuum = 494 nm
refractive index of water with respect to air = 1.333
Let the wavelength of light in water is λ.
The frequency of the light remains same but the speed and the wavelength is changed as the light passes from one medium to another.
By using the definition of refractive index

where, n be the refractive index of water with respect to air
By substituting the values, we get

λ = 370.6 nm
Thus, the wavelength of light in water is 370.6 nm.
Answer: 271.4 s
Explanation:
We are told the top speed (maximum speed)
the car has is:
taking into account 
And the car's average acceleration
is:

Since:
(1)
Where:
is the car's final speed (top speed)
because it starts from rest
is the time it takes to reach the top speed
Finding this time:
(2)
(3)
(4)
Now we have to find the distance
the car traveled at this maximum speed with the following equation:
(5)
Isolating
:
(6)
(7)
(8)
On the other hand, we know the total distance
traveled by the car is:
Hence the remaining distance is:
(9)
(10)
So, we can calculate the time
it took to this car to travel this remaining distance
at its top speed
, with the following equation:
(11)
Isolating
:
(12)
(13)
(14)
With this time
and the value of
calculated in (4) we can finally calculate the total time
:
(15)
(16)
The speed of the tennis ball is 8 km/h when Alana throws the ball behind at the speed of 11 km/h.
<h3>What is the
frame of
reference?</h3>
It is a point from where the motion is observed. The speed changes with the frame of reference.
For the person standstill on the sidewalk, If Alana throw the ball in the front direction, The speed will be,
19+11 = 30 km/h
It Alana just leave the ball, the speed,
19 +0 = 19 km/h
If Alana throws the ball behind her at the speed of 19 km/h. The speed of the ball for a sidewalk observer,
19 +(-19 ) = 0 km/h
Thus, when Aana throw the ball behind the velocity will be negative,
So,
19 + (-11 ) = 8 km/h
Therefore, the speed of the tennis ball is 8 km/h when Alana throws the ball behind at the speed of 11 km/h.
Learn more about Frame of reference:
brainly.com/question/9820962