Answer:
Explanation:
Consider the axis diagram attached.
Given:
Ey = Ez = 0
Eₓ = - 4x N/C · m
Since electric field is in x direction, potential difference would be:
Here we integrate between limits 0 and 4.40 which is distance between A and B along x-axis.
![V_{b} - V_{a} = -4 \left[\begin{array}{ccc}\frac{x^{2} }{2} \end{array}\right]^{4.40}_{0}](https://tex.z-dn.net/?f=V_%7Bb%7D%20-%20V_%7Ba%7D%20%3D%20-4%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D%5Cfrac%7Bx%5E%7B2%7D%20%7D%7B2%7D%20%5Cend%7Barray%7D%5Cright%5D%5E%7B4.40%7D_%7B0%7D)
When a body strictly moves on a curve, it's velocity at a point is tangential to the curve at that point.
Centripetal acceleration is the acceleration that a body experiences by the virtue of change in it's tangential velocity. It is directed towards the centre and mathematically is v^2/R where v is the speed at the instant.
So, 18 = v^2/R
v^2 = 504
v = 6√14
A. 14 gallons.
Scalar quantities require magnitude to describe them. They do not need direction to be described. 14 gallons is the mass of the gallons which is a scalar quantity.
"2 km/hr/s" means that in each second, its engines can increase its speed by 2 km/hr.
If it keeps doing that for 30 seconds, its speed has increased by 60 km/hr.
On top of the initial speed of 20 km/hr, that's 80 km/hr at the end of the 30 seconds.
This whole discussion is of <em>speed</em>, not velocity. Surely, in high school physics,
you've learned the difference by now. There's no information in the question that
says anything about the train's <em>direction</em>, and it was wrong to mention velocity in
the question. This whole thing could have been taking place on a curved section
of track. If that were the case, it would have taken a team of ace engineers, cranking
their Curtas, to describe what was happening to the velocity. Better to just stick with
speed.
