Given :
The ball of a ballpoint pen is 0.5 mm in diameter and has an ASTM grain size of 12.
To Find :
How many grains are there in the ball?
Solution :
Volume of ball of the ballpoint is :

Now, grain size of 12 has about 520000 grains/mm³.
Therefore, number of grains are :

Answer:
8.8 kN
Explanation:
V = 2 m³, W = 40 kN, SG = 1.59
Bouyant force N = 1.59 * 1000 kg/m³ * 9.81 N/kg * 2 m³ = 31.2 kN
So the weight becomes 40 - 31.2 = 8.8 kN
Answer:
840000 J/min
Explanation:
Area = A = 0.1 m²
Bottom of pot temperature = 200 °C
Thermal conductivity = k = 14 J/sm°C
Thickness = L = 1 cm = 0.01 m
Temperature of boiling water = 100 °C
From the law of heat conduction
Q = kAΔT/L
⇒ Q = 14×0.1×(200-100)/0.01
⇒ Q = 14000 J/s
Converting to J/minute
Q = 14000×60 = 840000 J/min
∴ Heat being conducted through the pot is 840000 J/min
B,a current flows through the wire