Sometimes arithmetic problems can be solved much more easily using the dimensional analysis approach. You focus on the units of the given information. Then, you manipulate them applying the laws of algebra where like units cancel, in order to end up with the unit of the unknown.
Given:
-50 nc/step
31 steps
Unknown: charge
Thus,
Charge = -50 nc/step * 31 steps =<em> -1550 nc</em>
Answer:
28 miles
Explanation:
3,223 meters/day x 14 days = 45,122 meters
1 meter = 3.28 feet
45,122 meters = 148,000 feet
5280 feet = 1 mile
148,000 feet = 28 miles
Answer: 
The ball was thrown at the speed of
.
Maximum height achieved is 
Time of flight is t.
Now, the time the ball takes to achieve maximum height = the time taken by ball to fall back = 
let us just consider the second half of the flight. At
, the velocity would be zero. let us consider as the initial velocity for the second half of the flight i.e. 
Using the equation of motion:

where,
is the final velocity, a is the acceleration, t is the time taken.
Because the ball would fall under gravity, hence a=g and time of flight would be t/2

Answer:
The part of a circuit that increases the electric potential of the electrons is the battery.
Answer:
If air in a pump is squeezed more, then the air gets hotter because energy is added to it.
Explanation:
A hypothesis is a simple scientific guess that can be investigated. It usually adopts the if -then and because approach to relate variables to the expect output.
The most fitting statement of hypothesis that can be investigated is that "If air in a pump is squeezed more, then the air gets hotter because energy is added to it".
We can find the volume of the air, the pressure of the pump and temperature and discern their relationships.
Based on the kinetic theory, pressure causes increasing collisions between particles and hereby, a gas will be hotter.