The rule that is used to get the strength of magnetic field at the center of solenoid (B) is:
B = <span>µ x n x I where:
</span>µ is the permeability of the medium where the solenoid is based. In this problem, the medium is air which means that µ = <span>µ </span><span>o = 4 pi x 10^-7 Tm/A
</span>I is the current passing (I = 4 amperes)
n is the number of turns per unit length (5000 turns)
Substituting in the mentioned equation, we find that:
B = 4 x 3.14 x 10^-7 x 5000 x 4 = 25.132 mT
Answer: C. Metal transfers heat away from the skin by conduction, creating the sensation of coolness.
Explanation: The skin releases heat into the metal bowl since there is a difference in temperature between the two objects. So heat is taken away from the hand abd transfers into the metal bowl by conduction creating a cooler sensation.
Answer: 0.28 m/s
Let
M1 = mass of Steve
V1 = velocity of Steve
M2 = mass of can
V2 = velocity of can
Because momentum is a conserved quantity:
P1 - P2 = 0
So
M1*V1 - M2*V2 = 0
78.0kg(V1) - 2.5kg(8.7m/s) = 0
78.0(V1) = 21.75
V1= 0.28 m/s