Amass m = 0.85 kg hangs at the end of a vertical spring whose top end is fixed to the ceiling. the spring has spring constant k = 65 n/m and negligible mass. at time t = 0 the mass is released from rest at a distance d = 0.45 m below its equilibrium height and undergoes simple harmonic motion with its position given as a function of time by y(t) = a cos(ωt – φ). the positive y-axis points upward.

(a) find the angular frequency of the oscillation, in radians per second.
( b) determine the value of φ, in radians.
(c) calculate coefficient a, in meters.
(d) what is the mass’s velocity along the y-axis, in meters per second, at time t1 = 0.15 s?
(e) what is the magnitude of the mass’s maximum acceleration, in meters per second squared?
(f) what is the magnitude of the mass s maximum acceleration, in meters per second squared?

their crystal patterns have been disrupted by stress

multiple allele inheritance is traits controlled by more than 2 alleles (ex: pigeons having 3 alleles of one gene govern their feather color).

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

from wikipedia