Answer:
U = 11.67 W/m² °C
Explanation:
Inner diameter, d = 2.5 cm = 0.025 m
Thickness of the wall, t = 2 mm = 0.002 m
thus, the outer diameter, D = d + 2t = 0.025 + 2 x 0.002 = 0.029 m


Now, based on outside convection heat transfer
we have

on rearranging, we get

where,
are the perimeter respective to inner and and outer diameter
on substituting the values, we get

or
U = 11.67 W/m² °C
Answer:
115 km/h
Explanation:
= Mass of car A = 690 kg
= Mass of car B = 520 kg
g = Acceleration due to gravity = 9.81 m/s²
a = Acceleration
u = Initial velocity
v = Final velocity



Converting to km/h

Initial velocity of car A = 115 km/h
Answer:
The volume of the cylinder is 
Explanation:
Given that,
The height of the cylinder is 13 cm
Radius of the cylinder is 4 cm
We need to find the volume of the cylinder. The formula that is used to find the volume of a cylinder is given by :

So, the volume of the cylinder is 
Given Information:
Voltage of circuit A = Va = 208 Volts
Current of circuit A = Ia = 40 Amps
Voltage of circuit B = Vb = 120 Volts
Current of circuit B = Ib = 20 Amps
Required Information:
Ratio of power = Pa/Pb = ?
Answer:
Ratio of power = Pa/Pb = 52/15
Explanation:
Power can be calculated using Ohm's law
P = VI
Where V is the voltage and I is the current flowing in the circuit.
The power delivered by circuit A is
Pa = Va*Ia
Pa = 208*40
Pa = 8320 Watts
The power delivered by circuit B is
Pb = Vb*Ib
Pb = 120*20
Pb = 2400 Watts
Therefore, the ratio of the maximum power delivered by circuit A to that delivered by circuit B is
Pa/Pb = 8320/2400
Pa/Pb = 52/15