The Lorentz force exerted on a charge moving in a magnetic field is given by:
where
q is the charge
v is the speed of the charge
B is the intensity of the magnetic field
is the angle between the directions of the field and of the velocity
The data we have in our problem are:
If we substitute these data and we rearrange the initial equation, we can calculate the speed of the particle:
so, the correct answer is
<span>1.1 × 104 m/s</span>
Answer:
25 cm²
Explanation:
Meters and centimeters are both the units for measuring length. The SI unit of measuring length is meters.
Area is the quantity which measures the cross-section occupied by the object.
Thus,
Given that = Area = 0.0025 m²
To convert into cm²
1 m = 100 cm
So, 1 m² = 10000 cm²
So,
<u>Area = 0.0025 × 10000 cm² = 25 cm²</u>
The correct answer is option C. insulator.
An insulator material<span> has a high resistivity and prevents the movement of electrons. It is a hindrance in the path of electrons & resists the current flow.
The conductor conducts electrons as it offers very less resistance. A battery provides voltage to the circuit.
Hence, option (c) is correct. </span>
Answer:
a) r eq = -a/(2b)
b) k = a/r eq = -2b
Explanation:
since
U(r) = ar + br²
a) the equilibrium position dU/dr = 0
U(r) = a + 2br = 0 → r eq= -a/2b
b) the Taylor expansion around the equilibrium position is
U(r) = U(r eq) + ∑ Un(r eq) (r- r eq)^n / n!
,where Un(a) is the nth derivative of U respect with r , evaluated in a
Since the 3rd and higher order derivatives are =0 , we can expand until the second derivative
U(r) = U(r eq) + dU/dr(r eq) (r- r eq) + d²U/dr²(r eq) (r- r eq)² /2
since dU/dr(r eq)=0
U(r) = U(r eq) + d²U/dr²(r eq) (r- r eq)² /2
comparing with an energy balance of a spring around its equilibrium position
U(r) - U(r eq) = 1/2 k (r-r eq)² → U(r) = U(r eq) + 1/2 k (r-r eq)²
therefore we can conclude
k = d²U/dr²(r eq) = -2b , and since r eq = -a/2b → -2b=a/r eq
thus
k= a/r eq