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:
A. 0.199 J
B. 0.0663 C
C = 0.0221 F
D. 12.68 ohms
Explanation:
From the question:
time duration, t = 0.28 seconds
Average power, P = 0.71 W
Average voltage, V = 3 V
A) Energy is given as:
E = P * t
=> E = 0.71 * 0.28 = 0.199 J
B) Electrical energy is also given as:
E = qV
where q = charge
=> q = E / V
∴ q = 0.199 / 3 = 0.0663 C
C) Capacitance is given as charge over voltage:
C = q / V
=> C = 0.0663 / 3 = 0.0221 F
D) Electrical power, P, can also be given as:
P = 
where R = resistance
=> R = 
R = 
Answer:
110.87 dB
Explanation:
(I got it right on Acellus)
I= P/4(pi)r^2 = 60/4(pi)6.25^2
60/4(pi)6.25^2=0.12223
B=10log(I/Io)
B=10log(0.12223/1*10^-12) = 110.87 dB
111 in sigfigs
Answer:

Explanation:
From work energy theorem
Work done by all forces = Change in kinetic energy
Lets take
m= mass of object
h=height from the ground surface
initial velocity of object = 0 m/s
The final velocity of object is v
Work done by gravitational force = m g . h
The final kinetic energy = 1/2 m v²
So
Work done by all forces = Change in kinetic energy
m g h = 1/2 m v² - 0
v² = 2 g h

Answer:
option C
Explanation:
given,
mass of water = 4 Kg
Water is heated to = 800 W
time of immersion = 10 min
= 10 x 60 = 600 s
using equation of specific heat
Q = m S ΔT
S is the specific heat capacity of water which is equal to 4182 J/kg°C.
and another formula of heat
Q = Pt
now,
P t = m S ΔT
800 x 600 = 4 x 4182 x ΔT
ΔT = 29° C
temperature increased is equal to ΔT = 29° C
Hence, the correct answer is option C