Answer:

Explanation:
It is given that, a proton moves at constant velocity, through a region in which there is an electric field and a magnetic field such that,
The electric field is, E = 800 V/m
Magnetic field, B = 0.25 T
We know that the net force in the region of magnetic and electric field is given by Lorentz forces. But here, the proton moves with constant velocity. So, the net force acting on it is 0.
i.e.

Hence, this is the required solution.
Answer:
d
Explanation:
Solution:-
- The Quantity of theory of money states:
M * V = P * Y
Where,
M = Money supply
V = Velocity of money exchange
P = The price level
Y = Real GDP
- By re-arranging the formula and solving for "V" we have:
V = P*Y / M
- The expression on right hand side increases if exchange of dollars increases.
Answer:
39.240 W
Explanation:
Let's start by calculating the work done by the engine. We can assume that it is the same work done by the weight of the object to bring it from 40m to the surface: as much energy it takes to bring it up, the same ammount it takes to bring it down. Said work is 
At this point we can simply apply the definition of power, that is
, to get the power of the engine is 
Here, Initial momentum = mu = 6*2 = 12 Kg m/s
Final momentum = mv = 6*4 = 24 Kg m/s
In short, Your Answer would be Option C
Hope this helps!
This question is poorly stated, but I assume you mean what conditions are needed. It would have to be cold outside, correct?