Answer:
14 rev
Explanation:
= initial angular velocity = 2.5 revs⁻¹
= final angular velocity = 0.8 revs⁻¹
= Angular acceleration = - 0.2 revs⁻²
= Angular displacement
Using the equation

So the number of revolutions are 14
Answer:
The torque in the coil is 4.9 × 10⁻⁵ N.m
Explanation:
T = NIABsinθ
Where;
T is the torque on the coil
N is the number of loops = 9
I is the current = 7.8 A
A is the area of the circular coil = ?
B is the Earth's magnetic field = 5.5 × 10⁻⁵ T
θ is the angle of inclination = 90 - 56 = 34°
Area of the circular coil is calculated as follows;

T = 9 × 7.8 × 0.0227 × 5.5×10⁻⁵ × sin34°
T = 4.9 × 10⁻⁵ N.m
Therefore, the torque in the coil is 4.9 × 10⁻⁵ N.m
Answer:
A. 0.432
B. -1.92
C. 1.44 units/second
D. -3.2 units/second
Explanation:
A. To calculate her x position, we just use the following equation of motion to find the distance traveled:

here s = displacement
t = time (in seconds)
a = acceleration
Solving for the distance, we get:

s = 0.432 m
Since 0.432 meters east is equals to 0.432 meter in the positive x-direction, the x position is also 0.432.
B. Since the skater has a constant v - velocity of -3.2 m/s, (south means negative y axis), the total distance traveled is:
Distance = speed * time = -3.2 * 0.6 = -1.92 m
The answer is -1.92 units in the y-axis.
C. The x velocity component is the final speed in the east direction, which is going to be:


v = 1.44 units/second (in positive x direction)
D. Her y velocity component does not change, since the velocity towards the south is a constant 3.2 m/s
Thus the answer is -3.2 units/second in the y-axis.
Answer:
(a) Angle of incidence for violet is more than the angle of incidence for red
(b) 2.4°
Explanation:
refractive index for violet , v = 1.66
refractive index for red, nR = 1.61
wavelength for violet, λv = 400 nm
wavelength for red, λR = 700 nm
Angle of refraction, r = 30°
(a) Let iv be the angle of incidence for violet.
Use Snell,s law
nv = Sin iv / Sin r
1.66 = Sin iv / Sin 30
Sin iv = 0.83
iv = 56°
Use Snell's law for red
nR = Sin iR / Sin r
where, iR be the angle of incidence for red
1.61 = Sin iR / Sin 30
Sin iR = 0.805
iR = 53.6°
So, the angle of incidence for violet is more than red.
(b) iv - iR = 56° - 53.6° = 2.4°