During that period of time, the bird's displacement was 4 km east. So its velocity was (4km east)/(11hrs). That's 0.36 km/hour east. (rounded)
The vessel must also have red and green side lights.
The red light is placed on the port (left) side of the boat while the green light is placed on the starboard (right) side of the vehicle. The white lights are on both the masthead (front) and stern (rear) of the boat, unless the vessel is less than 39.4 feet, in which case the front and rear white light may be combined as only one white light.
Speed is the rate of change <span>of distance.</span>
Answer:
4m/s
Explanation:
The motion is in downward direction, and the boat is moving with constant velocity, the position of the boat horizontally is 12m before the key fall.
The height difference "h"= ( y- y°)= 45 m
We can determine the needed time the key requires to reach the water using the expression from Newton's law
h= v(o) + 1/2 at^2
g= acceleration due to gravity= 9.8m/s^2
h= v(o) + 1/2 gt^2 -------------------------eqn*)
V(o)= 0 for the key= initial velocity
h= height that the key falls= 45m
If we substitute the above values into eqn(*) we have
We can make t^2 subject of the formula since v(0)= 0
t^2= h/(1/2 g)
= 45/(1/2× 9.8)
t^2= 45/4.9=9.18
t= √9.18
t=3.03 secs
Since the boat was moving with constant velocity,
Then Velocity= distance/ time
= 12/3.03
Velocity= 4m/s
Hence, the speed of the boat is 4m/s
When a snowball turns into a puddle of water, we know that (the snow ball gains energy and changes from a solid to liquid).
This is correct due to the fact that particles of the snowball are gaining speed and so it is heating up, when the solid's temperature reaches the melting point, it will become a liquid.
Therefore, D is the correct answer.
