Answer:
Electric field acting on the electron is 127500 N/C.
Explanation:
It is given that,
Mass of an electron, 
Charge on electron, 
Initial speed of electron, u = 0
Final speed of electron, 
Distance covered, s = 2 cm = 0.02 m
We need to find the electric field required. Firstly, we will find the acceleration of the electron from third equation of motion as :
According to Newton's law, force acting on the electron is given by :
F = ma
Electric force is given by :
F = q E, E = electric field
E = 127500 N/C
So, the electric field is 127500 N/C. Hence, this is the required solution.
Answer:
Explanation:
Torque is defined as the cross product between the position vector ( the lever arm vector connecting the origin to the point of force application) and the force vector.
Due to the definition of cross product, the magnitude of the torque is given by:
Where 
is the angle between the force and lever arm vectors. So, the length of the lever arm (r) is minimun when 
is equal to one, solving for r:
You look up the element in the periodic table. Subtract the atomic number (small number) from the mass number (big number). The answer is the number of neutrons.
Answer:
The steps are outlined in the explanation below.
Explanation:
The average velocity is derived midpoint from the initial to the final velocity. Here is the proof:
Find the total displacement:
let the displacement be given by the letter s
Then since the average velocity is defined as: 
where t = final time
t₀ = initial time
v = final speed
v₀ = initial time
where x denotes the position, then
where v = 
and dx = change in distance with respect to time.
Answer:
1.61 second
Explanation:
Angle of projection, θ = 53°
maximum height, H = 7.8 m
Let T be the time taken by the ball to travel into air. It is called time of flight.
Let u be the velocity of projection.
The formula for maximum height is given by
By substituting the values, we get
u = 9.88 m/s
Use the formula for time of flight
T = 1.61 second
