Explanation:
It is given that,
Magnetic field, B = 0.1 T
Acceleration, 
Charge on electron, 
Mass of electron, 
(a) The force acting on the electron when it is accelerated is, F = ma
The force acting on the electron when it is in magnetic field, 
Here, 
So, 
Where
v is the velocity of the electron
B is the magnetic field
v = 341250 m/s
or
So, the speed of the electron is 
(b) In 1 ns, the speed of the electron remains the same as the force is perpendicular to the cross product of velocity and the magnetic field.
Answer:
70 cm
Explanation:
0.5 kg at 20 cm
0.3 kg at 60 cm
x = Distance of the third 0.6 kg mass
Meter stick hanging at 50 cm
Torque about the support point is given by (torque is conserved)
The position of the third mass of 0.6 kg is at 20+50 = 70 cm
Answer:
145.43 N
Explanation:
Weight is given by (mg)
where m = mass of the body
g = acceleration due to gravity
mass is constant everywhere and is equal to 77.1 kg, both on the earth and on the moon.
But the acceleration due to gravity exerted by the moon near the moon's surface is 16.6% that of Earth,
g(moon) = 0.166 g(earth) = 0.166 × 9.8 = 1.6268 m/s²
Weight on the moon = mg(moon) = (77.1×1.6268) = 125.43 N
Answer:
Power = 180 Watt.
Explanation:
W = Work done = m x g x H.
m = mass of the body.
g = acceleration due to gravity = 9.8 m/s^2.
W = weight of the body = m x g = 720 N.
H = height of the body = 5 m.
t = Time = 20 s.
Plugging the above values in the formula we get:
W = 720 x 5 = 3600 J.
Power = 
= 
= 180 Watt.
Therefore the required value of power = 180 Watt.
Answer:
a ) 2.13 X 10⁶ m/s .
b ) 1.28 X 10⁶ m/s
Explanation:
When electrons are repelled by negative plates and attracted by positive plates , it will increase their kinetic energy.
Increase in their energy = 4.15 eV
= 4.5 X 1.6 X 10⁻¹⁹ J
= 6.64 x 10⁻¹⁹ J
Initial kinetic energy
= 1/2 mv²
= 1/2 x 9.1 x 10⁻³¹ x ( 1.76 x 10⁶)²
= 14.09 X 10⁻¹⁹ J
Total energy
= 6.64 x 10⁻¹⁹+14.09 X 10⁻¹⁹
= 20.73 x 10⁻¹⁹
If V be the increased velocity
1/2 m V² = 20.73 X 10⁻¹⁹
.5 X 9.1 X 10⁻³¹ V² = 20.73 X 10⁻¹⁹
V = 2.13 X 10⁶ m/s .
b ) When electrons are released from positive plate , their speed are reduced because of attraction between electrons and positively charge plates.
Initial kinetic energy
= 14.09 x 10⁻¹⁹ J (see above )
reduction in kinetic energy
= 6.64 x 10⁻¹⁹ J ( See above )
Total energy with electron -
= 14.09 x 10⁻¹⁹ - 6.64 x 10⁻¹⁹
= 7. 45 x 10⁻¹⁹ J .
If V be the energy of electrons reaching the negative plate,
1/2 m V² =7. 45 x 10⁻¹⁹
V = 1.28 X 10⁶ ms⁻¹
