To make something electrical you need electricity and the wires will turn a magnet into an electromagnet.
or for a short answer: <span>1) soft iron core 2) coil of insulated wire 3)source of electricity</span>
Answer:
a. L = μ₀AN²/l b. 1.11 × 10⁻⁷ H
Explanation:
a. The magnetic flux through the solenoid, Ф = NAB where N = number of turns of solenoid, A = cross-sectional area of solenoid and B = magnetic field at center of solenoid = μ₀ni where μ₀ = permeability of free space, n = number of turns per unit length = N/l where l = length of solenoid and i = current in solenoid.
Also, Li = Ф where L = inductance of solenoid.
So, Li = NAB
= NA(μ₀ni)
= NA(μ₀Ni/l)
Li = μ₀AN²i/l
dividing both sides by i, we have
So, L = μ₀AN²/l
b. The self- inductance, L = μ₀AN²/l where
A = πd²/4 where d = diameter of solenoid = 0.150 cm = 1.5 × 10⁻³ m, N = 50 turns, μ₀ = 4π × 10⁻⁷ H/m and l = 5.00 cm = 5 × 10⁻² m
So, L = μ₀AN²/l
L = μ₀πd²N²/4l
L = 4π × 10⁻⁷ H/m × π(1.5 × 10⁻³ m)²(50)²/(4 × 5 × 10⁻² m)
L = 11,103.3 × 10⁻¹¹ H
L = 1.11033 × 10⁻⁷ H
L ≅ 1.11 × 10⁻⁷ H
Given that,
Time = 0.5 s
Acceleration = 10 m/s²
(I). We need to calculate the speed of apple
Using equation of motion
Where, v = speed
u = initial speed
a = acceleration
t = time
Put the value into the formula
(III). We need to calculate the height of the branch of the tree from the ground
Using equation of motion
Put the value into the formula
(II). We need to calculate the average velocity during 0.5 sec
Using formula of average velocity
Where, 
= final position
= initial position
Put the value into the formula
Hence, (I). The speed of apple is 5 m/s.
(II). The average velocity during 0.5 sec is 2.5 m/s
(III). The height of the branch of the tree from the ground is 1.25 m.
Answer:
12.5 m/s
Explanation:
From the question given above, the following data were obtained:
Initial velocity (u) = 0 m/s
Height (h) = 8 m
Final velocity (v) at 8 m above the lowest point =?
NOTE: Acceleration due to gravity (g) = 9.8 m/s²
The velocity of the roller coaster at 8 m above the lowest point can be obtained as follow:
v² = u² + 2gh
v² = 0² + (2 × 9.8 × 8)
v² = 0 + 156.8
v² = 156.8
Take the square root of both side
v = √156.8
v = 12.5 m/s
Therefore, the velocity of the roller coaster at 8 m above the lowest point is 12.5 m/s.
