The spoon to transfer 40 J of energy to your hand is descibed as follows
<u>Explanation:</u>
Given area of cross section of copper spoon is A = 20mm into 1.5 mm
temperature difference is DT = (100 minus 35) = 65 0C
length of the spoon is l = 18 cm,
amount of heat should be transfer Q = 40 J
coefficient of thermal conductivity of copper k = 400 W by mk
we know that the thermal conductivity is Q by t = k into A into DT by l
t = Q into l by k into A into DT
t = (40 into 0.18) by 
t = 9.23 s
The correct answer is:
<span>paramagnetism
In fact, paramagnetic materials, when they are placed in a magnetic field, they form an internal magnetic field parallel to the external one and in the same direction. However, unlike ferromagnetic materials, they do not retain their magnetization, so when the external magnetic field is removed, their internal induced magnetic field disappears.</span>
Answer:
18 W
Explanation:
Applying,
P = V²/R.................. Equation 1
Where P = Power of both glowing bulbs, V = Voltage, R = Combined Resistance of both bulbs
Since: It is a series circuit,
Then,
R = R1+R2............. Equation 2
Where R1= Resistance of the first bulb, R2 = Resistance of the second bulb
Given: R1 = R2 = 8 Ω
Substitute into equation 1
R = 8+8
R = 16 Ω
Also Given: V = 12 V
Substitute into equation 1
P = 12²/8
P = 144/8
P = 18 W
<span>Using Coulomb's law: k*(-0.3)*(-0.3)/(d^2)=19.2
D is the distance between the two negative charges</span>
