Aturntable rotates counterclockwise at 76 rpm . a speck of dust on the turntable is at 0.45 rad at t=0. what is the angle of the speck at t = 8.0 s ? your answer should be between 0 and 2ï rad.

64.08 rad

Explanation:

f = 78 rpm = 76 / 60 rps

θ = 0.45 rad, t = 8 s

(θ2 - θ1) / t = ω

θ2 - θ1 = 2 x 3.14 x 76 x 8 / 60 = 63.63

Angle turns from initial position = 0.45 + 63.63 = 64.08 rad

the answer is the first electromagnet (a). this is because it has more coils around the ferromagnetic material. increasing the number of coils increases the surface area in which the metal interacts with the current in the coil. this enables more atoms in the metal to become aligned hence becoming more magnetized.