mark me the brainiest here
average speed (in km/h) of a car stuck in traffic that drives 12 kilometers in 2 hours.
Answer:
The second classmate is right.
Explanation:
The height of first summit provides the potential energy it will use to climb the following ones.
Ep = m * g * h
Where
m: mass
g: acceleration of gravity
h: height
When the train goes downwards the potential energy is converted into kinetic energy (manifested as speed) and when it climbs it consumes its kinetical energy. As long as no summit is taller than the first the train should have enough energy to climb them.
Also it must be noted that friction also consumes energy, and if the track is too lomg all the energy might be consumed by it.
Answer:
option (c) is the correct answer which is zero acceleration.
Explanation:
It is given in the question that the velocity is constant.
Now,
the options are provided in relation to the acceleration.
We know,
acceleration is rate of change of velocity per unit time i.e
acceleration =
since, the change in velocity is given to be zero,
thus, dV/dt = 0
hence,
acceleration = 0
therefore, option (c) is the correct answer which is zero acceleration.
Answer:
The required heat flux = 12682.268 W/m²
Explanation:
From the given information:
The initial = 25°C
The final = 75°C
The volume of the fluid = 0.2 m/s
The diameter of the steel tube = 12.7 mm = 0.0127 m
The fluid properties for density
= 1000 kg/m³
The mass flow rate of the fluid can be calculated as:




To estimate the amount of the heat by using the expression:

q = 0.0253 × 4000(75-25)
q = 101.2 (50)
q = 5060 W
Finally, the required heat of the flux is determined by using the formula:



q" = 12682.268 W/m²
The required heat flux = 12682.268 W/m²