Speed = (distance traveled) / (time to travel the distance).
Strange as it may seem, 'velocity' is completely different.
Velocity doesn't involve the total distance traveled at all.
Instead, 'velocity' is based on 'displacement' ... the distance
between the start-point and end-point, regardless of the route
taken to get there. So the displacement in driving once around
any closed path is zero, because you end up where you started.
Velocity =
(displacement during some time)
divided by
(time for the displacement)
AND the direction from the start-point to the end-point.
For the guy who drove 15 km to his destination in 10 min, and then
back to his starting point in 5 min, (assuming he returned by way of
the same 15-km route):
Speed = (15km + 15km) / (10min + 5min) = (30/15) (km/min)
= 2 km/min.
Velocity = (end location - start position) / (15 min) = Zero .
Answer:
The time that will pass between the feeling and hearing the explosion is 2,86 secs
Explanation:
First, let's calculate the time that the wave takes to travel until the actors feel the explosion:
Now, the time that pass while the actors hear the sound is:
<em>(Remember that the sound speed in the air is 340 m/s on average)</em>
So, the time between the feeling and hearing is 3,23 - 0,37 = 2,86 secs
Answer:
The value is 
Explanation:
Generally the thermal efficiency is mathematically represented as
substituting [ 627°C + 273 = 900K ] for 
and [ 90°C + 273 = 333K ] for 
So
=>
Answer: 
Explanation:
The de Broglie wavelength 
is given by the following formula:
(1)
Where:
is the Planck constant
is the momentum of the atom, which is given by:
(2)
Where:
is the mass of the electron
is the velocity of the electron
This means equation (2) can be written as:
(3)
Substituting (3) in (1):
(4)
Now, we only have to find :
>>> This is the de Broglie wavelength of the electron
