Answer:
change in height is 1.664 mm
Explanation:
Given data
drops = 3.00 mm
diameter = 5.00 cm = 0.05 mm
decrease = 350 cm^3
temperature = 95°C to 44.0°C
to find out
the decrease in millimeters in level
solution
we will calculate here change in volume so we can find how much level is decrease
change in volume = β v change in temp ...............1
here change in volume = area× height
so =
/4 × d² h
so we can say change in volume =
/4 × d² × change in height .......2
so from equation 1 and 2 we calculate change in height
( β(w) -β(g) )× v× change in temp =
/4 × d² × change in height
change in height = 4 × ( β(w) -β(g) ) v× change in temp /
/4 × d²
put all value here
change in height = 4 × ( 210 - 27 )(350 )
× (95-44) /
/4 × 0.05²
change in height is 1.664 mm
Average speed is worked out from dividing distance by time.
Answer: Q=5.46 L/s
COP=2.58
Explanation:
Given that
Cp = 4.18 kJ/(kg.C
density = 1 kg/L
Heat rejected Qr= 570 kJ/min
Power in put W= 2.65 KW
From first law of thermodynamics
U = W+ q
q = Heat absorbed
U = internal energy
W = workdone
U = 570 kJ/min = 9.5 KW
9.5 = 2.65 + q
q = 6.85 KW
COP = q/W
COP = 6.58 / 2.65
COP=2.58
Lets take volume flow rate is Q
So mass flow rate of water m = ρ Q
q = m Cp ΔT
6.85 = 1 x Q x 4.18 ( 23-5)
Q=0.091 L/min
Q=5.46 L/s
The given data is incomplete. The complete question is as follows.
At an accident scene on a level road, investigators measure a car's skid mark to be 84 m long. It was a rainy day and the coefficient of friction was estimated to be 0.36. Use these data to determine the speed of the car when the driver slammed on (and locked) the brakes. (why does the car's mass not matter?)
Explanation:
Let us assume that v is the final velocity and u is the initial velocity of the car. Let s be the skid marks and
be the friction coefficient and m be the mass of car.
Hence, the given data is as follows.
v = 0, s = 84 m,
= 0.36
According to Newton's law of second motion the expression for acceleration is as follows.
F = ma
= ma
= ma
a = 
Also,



= 
= 24.36 m/s
Thus, we can conclude that the speed of the car when the driver slammed on (and locked) the brakes is 24.36 m/s.