This question is incomplete, the complete question is;
A flat coil is in a uniform magnetic field. What angle between the magnetic field and the plane of the coil produces the maximum flux, and what angle produces 90% of the maximum flux
A) max: 0°
90% of max: 90°
B) max: 90°
90% of max: 45°
C) max: 90°
90% of max: 64°
D) max: 0°
90% of max: 26°
E) max: 90°
90% of max: 80°
Answer:
Option C) max: 90°
90% of max: 64° is the correct Answer
Explanation:
from the Suppose Area is A.
then flux at angular position O is
Ф = BAsin∅
⇒ Ф = βmaxSin∅
flux will be max when sin∅ = 1
therefore sin∅ = 1
∅ = sin⁻¹ 1
∅ = 90°
Now at 90% of max flux
Ф ⇒ 0.9βmax = βmax sin∅
0.9 = sin∅
∅ = sin⁻¹ (0.9)
∅ = 64.15° ≈ 64°
Therefore Max ∅ = 90°
90% flux = 64°
Option C) max: 90°
90% of max: 64° is the correct Answer
(4) a metal sphere with a charge of 1.0 × 10^−9 C <span>moved through a potential difference of 4.0 V would undergo the greatest change in electrical energy from the list. </span>
Answer:
4 m/s in negative acceleration
Explanation:
Acceleration = V- U/t
Where V is the final velocity
U is the initial velocity and t is the time given.
U = 65 m/s
V= 25 m/s
T= 10 seconds
Acceleration= (25m/s - 65m/s)÷10secs
= - 40/10
= -4m/s^2
Hence, it has a negative acceleration.
Answer:
a)
Y0 = 0 m
Vy0 = 15 m/s
ay = -9.81 m/s^2
b) 7.71 m
c) 3.06 s
Explanation:
The knowns are that the initial vertical speed (at t = 0 s) is 15 m/s upwards. Also at that time the dolphin is coming out of the water, so its initial position is 0 m. And since we can safely assume this happens in Earth, the acceleration is the acceleration of gravity, which is 9.81 m/s^2 pointing downwards
Y(0) = 0 m
Vy(0) = 15 m/s
ay = -9.81 m/s^2 (negative because it points down)
Since acceleration is constant we can use the equation for uniformly accelerated movement:
Y(t) = Y0 + Vy0 * t + 1/2 * a * t^2
To find the highest point we do the first time derivative (this is the speed:
V(t) = Vy0 + a * t
We equate this to zero
0 = Vy0 + a * t
0 = 15 - 9.81 * t
15 = 9.81 * t
t = 0.654 s
At this time it will have a height of:
Y(0.654) = 0 + 15 * 0.654 - 1/2 * 9.81 * 0.654^2 = 7.71 m
The doplhin jumps and falls back into the water, when it falls again it position will be 0 again. So we can equate the position to zero to find how long it was in the air knowing that it started the jump at t = 0s.
0 = Y0 + Vy0 * t + 1/2 * a * t^2
0 = 0 + 15 * t - 1/2 * 9.81 t^2
0 = 15 * t - 4.9 * t^2
0 = t * (15 - 4.9 * t)
t1 = 0 This is the moment it jumped into the air
0 = 15 - 4.9 * t2
15 = 4.9 * t2
t2 = 3.06 s This is the moment when it falls again.
3.06 - 0 = 3.06 s
Each hour 430 quintillion Joules of energy from the sun hits the Earth.
In a year it is very hard to determine because of the night and different light levels.
