Answer:
The difference in the length of the bridge is 0.42 m.
Explanation:
Given that,
Length = 1000 m
Winter temperature = 0°C
Summer temperature = 40°C
Coefficient of thermal expansion
We need to calculate the difference in the length of the bridge
Using formula of the difference in the length
Where, = temperature difference
=Coefficient of thermal expansion
L= length
Put the value into the formula
Hence, The difference in the length of the bridge is 0.42 m.
Answer:
Work out = 28.27 kJ/kg
Explanation:
For R-134a, from the saturated tables at 800 kPa, we get
= 171.82 kJ/kg
Therefore, at saturation pressure 140 kPa, saturation temperature is
= -18.77°C = 254.23 K
At saturation pressure 800 kPa, the saturation temperature is
= 31.31°C = 304.31 K
Now heat rejected will be same as enthalpy during vaporization since heat is rejected from saturated vapour state to saturated liquid state.
Thus, =
= 171.82 kJ/kg
We know COP of heat pump
COP =
=
= 6.076
Therefore, Work out put, W =
= 171.82 / 6.076
= 28.27 kJ/kg
Answer: 14.1 m/s
Explanation:
We can solve this with the Conservation of Linear Momentum principle, which states the initial momentum (before the elastic collision) must be equal to the final momentum
(after the elastic collision):
(1)
Being:
Where:
is the combined mass of Tubby and Libby with the car
is the velocity of Tubby and Libby with the car before the collision
is the combined mass of Flubby with its car
is the velocity of Flubby with the car before the collision
is the velocity of Tubby and Libby with the car after the collision
is the velocity of Flubby with the car after the collision
So, we have the following:
(2)
Finding :
(3)
(4)
Finally:
