Answer:
92.7 km
Explanation:
Since the magnetic field due to a solenoid is given by B = μ₀Ni/L where μ₀ = permeability of free space = 4π × 10⁻⁷ H/m, N = number of turns of solenoid, L = length of cardboard tube = 58 cm = 0.58 m, , i = current in wire = 2.5 A and l = length of wire.
So, N = BL/μ₀i
Since B = 2.0 kG = 2.0 × 10³ G = 2.0 × 10³ × 10⁻⁴ T = 2.0 × 10⁻¹ T = 0.2 T
So, substituting the variables into the equation, we have
N = BL/μ₀i
N = 0.2 T × 0.58 m/(4π × 10⁻⁷ H/m × 2.5 A)
N = 1.16 Tm/(31.416 × 10⁻⁷ HA/m)
N = 0.0369 × 10⁷ turns
N = 0.0369 × 10⁷ turns
N = 3.69 × 10⁵ turns
length of wire l = NC where N = number of turns and C = circumference of tube = πD where D = diameter of tube = 8.0 cm = 0.08 m
So, l = NC
= NπD
= πND
= π × 3.69 × 10⁵ turns × 0.08 m
= 0.9274 × 10⁵ m = 9.274 × 10⁴ m
= 92.74 × 10³ m
= 92.74 km
≅ 92.7 km
Answer:
0.785 m/s
Explanation:
Hi!
To solve this problem we will use the equation of motion of the harmonic oscillator, <em>i.e.</em>
- (1)
- (1)
The problem say us that the spring is released from rest when the spring is stretched by 0.100 m, this condition is given as:


Since cos(0)=1 and sin(0) = 0:


We get

Now it say that after 0.4s the weigth reaches zero speed. This will happen when the sping shrinks by 0.100. This condition is written as:

Since

This is the same as:

We know that cosine equals to -1 when its argument is equal to:
(2n+1)π
With n an integer
The first time should happen when n=0
Therefore:
π = 0.4ω
or
ω = π/0.4 -- (2)
Now, the maximum speed will be reached when the potential energy is zero, <em>i.e. </em>when the sping is not stretched, that is when x = 0
With this info we will know at what time it happens:

The first time that the cosine is equal to zero is when its argument is equal to π/2
<em>i.e.</em>

And the velocity at that time is:

But sin(π/2) = 1.
Therefore, using eq(2):

And so:

Answer:
12.5J
Explanation:
Given parameters:
Mass of bucket = 1.7kg
Height = 75cm = 0.75m
Unknown;
Work done on the bucket by the person = ?
Solution:
To solve this problem, we use the work done equation;
Work done = force x distance = mgh
m is the mass
g is the acceleration due to gravity
h is the height
Now, insert parameters and solve ;
Work done = 1.7 x 9.8 x 0.75 = 12.5J