A mass weighing 32 pounds stretches a spring 2 feet.
(a) Determine the amplitude and period of motion if the mass is initially released from a point 1 foot above the equilibrium position with an upward velocity of 6 ft/s.
(b) How many complete cycles will the mass have completed at the end of 4 seconds?
Answer:

Period =
seconds
8 cycles
Explanation:
A mass weighing 32 pounds stretches a spring 2 feet;
it implies that the mass (m) = 
m= 
= 1 slug
Also from Hooke's Law
2 k = 32
k = 
k = 16 lb/ft
Using the function:

(because of the initial position being above the equilibrium position)
( as a result of upward velocity)
NOW, we have:

However;
means

also implies that:


Hence, 





Period can be calculated as follows:
= 
=
seconds
How many complete cycles will the mass have completed at the end of 4 seconds?
At the end of 4 seconds, we have:


cycles
Answer:
Explanation:
magnetic field due to circular wire
= μ₀ i / 2r
i is current and r is radius of coil .
Magnetic fields due to inner coil
μ₀ x 20 / (2 x 9.5 x 10⁻²)
Magnetic field due to outer coil
= μ₀ x I / (2 x 19 x 10⁻²) , I is the current to be calculated
Total field
μ₀ x 20 /( 2 x 9.5 x 10⁻²) +μ₀ x I / (2 x 19 x 10⁻²) = 0
20 + I /2 = 0
I = - 40 A
Current required is 40 A , and it will be in opposite direction.
Answer:

Explanation:
The torque of a force is given by:

where
F is the magnitude of the force
d is the distance between the point of application of the force and the centre of rotation of the system
is the angle between the direction of the force and d
In this problem, we have:
, the force
, the distance of application of the force from the centre (0,0)
, the angle between the direction of the force and a
Therefore, the torque is

higher temp = higher energy = higher frequency = shorter wavelength