Answer:33.33 m/s
Explanation: In order to calculate this conversion we have to use:
1 mile = 1.6 km and also to convert Km/h to m/s the factor is 1000/3600
then we have: 75*1.6*0.27=33.33 m/s
Answer:

Explanation:
We know that for a capacitor
, where <em>Q </em>is the charge of one plate, <em>C</em> the capacitance and <em>V</em> the potential between the plates.
We also know that
, since
is the surface charge density and <em>A</em> the area of the plate (both equal in our case).
Putting all together:

Which for our values is:

Where we notice that the S.I. units combination FV/C must not have units (we can verify it directly from their definitions or we notice that
is enough to describe an area).
Answer:
The value of impulse of the net force on the ball during its collision with wall is 
The value of average horizontal force that the wall exerts on the ball during the impact is F = 15000 N
Explanation:
Mass of the ball = 0.5 kg
Horizontal velocity
= 20 
Velocity after collision
= - 10 
(A). Impulse of the net force on the ball during its collision with wall is

I = 0.5 × (20 + 10)

This is the value of impulse of the net force on the ball during its collision with wall.
(B). The magnitude of average horizontal force

Where F = Force
I = impulse & t = time interval = 0.001 sec

F = 15000 N
This is the value of average horizontal force that the wall exerts on the ball during the impact.
Masa is a concept that identifies that magnitude of a physical nature that allows indicating the amount of matter in a body. Within the International System , its unit is the kilogram ( kg . )
Answer:
electric energy ( power ) = 300000 W
Explanation:
given data
mechanical (hydroelectric) energy = 120 MJ/min = 2000000 J/s
efficiency = 15 % = 0.15
solution
we know that Efficiency of electric engine is expression as
Efficiency = Mechanical energy ÷ electric energy ......................1
and here dam electrical power output is
put here value in equation 1
electric energy ( power ) = Efficiency × Mechanical energy ( power )
electric energy ( power ) = 0.15 × 2000000 J/s
electric energy ( power ) = 300000 W