Answer:
The energy loss due to friction is 9465 J.
Explanation:
The given data :-
Mass of roller (m) = 500 kg.
The speed of roller coaster at height 27 m = 5.6 m/s.
Initial height of roller( h ) = 27 m.
The speed of roller coaster at bottom = 22 m/s.
Initial energy of roller at a height 27 m.
E₁ = K.E + P.E
E₁ = = = 7840 + 132435
E₁ = 140,275 J
The energy of roller at a height 2 m.
E₂ = K.E + P.E
E₂ = = = 121000 + 9810
E₂ = 130,810 J
The energy loss due to friction = E₁ - E₂ = 140,275 - 130,810 = 9465 J.
Answer:
The statement that refers to convection is Warm air rises and takes heat with it; eventually it cools and sinks
Explanation:
There are in general three modes of heat transfer: conduction, convection and radiation.
- In conduction, the heat transfers through contact
- In convection, the heat transfers through density difference
- In radiation, the heat transfers through wave motion
Consider first statement, 'Land and ocean absorb and re-emit heat from the sun'. Radiation is the only mode of heat transfer where there is no requirement for medium. The heat from sun to land and ocean has traveled by radiation. The process of re-emission also occurs in the same way.
Similarly in second statement the energy reflected of earth's atmosphere traveled by radiation and the last statement where sunlight travels through space without aid of fluids or solids refers to the process of radiation.
In third statement the warm air being less dense rises and takes heat with it; eventually it cools and thereby density increases which causes to sink. Here the movement of air is due to density difference, which concludes that this statement refers to convection
Answer: 20.73 m/s
Explanation:
The centripetal force is given by the following equation:
(1)
Where:
is the centripetal force
is the mass of the car
is the centripetal acceleration
Isolating :
(2)
(3)
(4)
Now, there is a relation between the centripetal acceleration and the tangential velocity:
(5)
Where is the tangential velocity and is the radius of the circular path, which can be found if we know its length :
(6)
(7)
(8)
(9)
Substituting (4) and (8) in (5)
(5)
Finding :
Answer:
The sum remains the same.
Explanation:
the question is incomplete, but I got this because i have done this before.
The more resistance you have the more you
have to push to make a current flow