Answer:
<em>20 m/s in the same direction of the bus.</em>
Explanation:
<u>Relative Motion
</u>
Objects movement is always related to some reference. If you are moving at a constant speed, all the objects moving with you seem to be at rest from your reference, but they are moving at the same speed as you by an external observer.
If we are riding on a bus at 10 m/s and throw a ball which we see moving at 10 m/s in our same direction, then an external observer (called Ophelia) will see the ball moving at our speed plus the relative speed with respect to us, that is, at 20 m/s in the same direction of the bus.
A baseball would hit the bat harder. This is because the baseball is a lot heavier and more dense than the plastic ball. The keyword that you're looking for is density. The baseball is dense.
The same speed of light, the fastest possible
darkness is just the absence of light therefore once light leaves darkness returns. making darkness have the same speed of light
Solution:
We have,
Power [P] = 25000 Watt
Mass [m] = 6000 kg
Height [h] = 20 metres
Time [t] = ?
Now,
P = W/t = F x d/t = mxgx h/t
Or, 25000 = 6000 x 10 x 20/25000 [.......g = 10
m/s^2]
Or, t = 6000 x 10 x 20/25000
Or, t = 1200/25
Therefore, t = 48 second
Hence, the required time for the crane to lift the load is 48 seconds.
