Because the light from it travels to you about 874 thousand times
as fast as the sound does, so the hearing part falls behind the seeing
part.
1) Pushing on a car will not always change the car's mechanical energy, but it does change yours since your physically using most of your energy to push the car.
2) In order for a cars kinetic energy to increase, the car has to be in motion when it is going down a hill, because when you go down hills and objects like that; you tend to increase in kinetic energy.
You have to have electrons that are in the materials conduction band. Then you apply a voltage across the material.
Answer:
0.25 m/s
Explanation:
From the law of conservation of momentum
Mu+ mu = Mv' + m v
M= mass of the astronaut = 80 kg
m= mass of the oxygen tank= 10 Kg
v= speedof the tank 2 m/s
u= initial velocity of the system= 0
If we substitute the values, we have
( 80× 0 )+(10×0)= [(80 x v )+ (10 x 2)]
0= 80v + 20
-20=80v
v= -0.25 m/s ( we have a negative value because the astronaut and the motion of the cylinder are in opposite direction)
Hence the velocity the astronaut start to move off into space is 0.25 m/s
We look at the criteria to select a car.
If we are not too rich, we have to bother about fuel efficiency. The mileage in terms
of km per liter or miles per gallon etc.
engine power - whether it is good enough over a slope (steep) that I may encounter
frequently with my family members.
internal space / total external size : or internal space / total price:
We find these numbers. after all , we make use of the internal space on seats.
we have to know its proportion in the total volume of the car.
the axle turning capability, wheel turning ability :
see the minimum radius and span required to turn a car in a U turn.
we have to bother about its pollution, emission level.
height / width ratio, which is important for the balance of the car.
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If we are looking at the economic point of view
monthly benefit/savings of using the car,converted into currency - Loan EMI
