Answer:
A
Explanation:if the things have the same charge they will repel makeing the ball move away form its positively charged guy = that the coil gun works.
Answer:
a

b

Explanation:
From the question we are told that
The speed of the airplane is 
The angle is 
The altitude of the plane is 
Generally the y-component of the airplanes velocity is

=> 
=>
Generally the displacement traveled by the package in the vertical direction is

=> 
Here the negative sign for the distance show that the direction is along the negative y-axis
=> 
Solving this using quadratic formula we obtain that

Generally the x-component of the velocity is

=> 
=>
Generally the distance travel in the horizontal direction is

=> 
=> 
Generally the angle of the velocity vector relative to the ground is mathematically represented as
![\beta = tan ^{-1}[\frac{v_y}{v_x } ]](https://tex.z-dn.net/?f=%5Cbeta%20%20%3D%20%20tan%20%5E%7B-1%7D%5B%5Cfrac%7Bv_y%7D%7Bv_x%20%7D%20%5D)
Here
is the final velocity of the package along the vertical axis and this is mathematically represented as

=>
=>
and v_x is the final velocity of the package which is equivalent to the initial velocity 
So
![\beta = tan ^{-1}[-130.05}{57.96 } ]](https://tex.z-dn.net/?f=%5Cbeta%20%20%3D%20%20tan%20%5E%7B-1%7D%5B-130.05%7D%7B57.96%20%7D%20%5D)

The negative direction show that it is moving towards the south east direction
Answer:
This will require 266.9 of heat energy.
Explanation:
To calculate the energy required to raise the temperature of any given substance, here's what you require:The mass of the material, m The temperature change that occurs, ΔT The specific heat capacity of the material,
c
(which you can look up). This is the amount of heat required to raise 1 gram of that substance by 1°C.
Here is a source of values of
c for different substances:
Once you have all that, this is the equation:
Q=m×c×ΔT(Q is usually used to symbolize that heat required in a case like this.)For water, the value of c is 4.186g°C So, Q=750×4.186×85=266=858=266.858