Answer:
2.1406 ×
m/sec
Explanation:
we know that energy is always conserved
so from the law of energy conservation

here V is the potential difference
we know that mass of proton = 1.67×
kg
we have given speed =50000m/sec
so potential difference 
now mass of electron =9.11×
so for electron

so the velocity of electron will be 2.1406×
m/sec
Answer:
240 ohms
Explanation:
From Ohms law we deduce that V=IR and making R the subject of the formula then R=V/I where R is resistance, I is current and V is coltage across. Substituting 120 V for V and 0.5 A for A then
R=120/0.5=240 Ohms
Alternatively, resistance is equal to voltage squared divided by watts hence 
Answer:
The electric field will be zero at x = ± ∞.
Explanation:
Suppose, A -2.0 nC charge and a +2.0 nC charge are located on the x-axis at x = -1.0 cm and x = +1.0 cm respectively.
We know that,
The electric field is

The electric field vector due to charge one

The electric field vector due to charge second

We need to calculate the electric field
Using formula of net electric field


Put the value into the formula




Put the value into the formula


If x = ∞, then the equation is be satisfied.
Hence, The electric field will be zero at x = ± ∞.
The correct answer is Mechanics