Answer:
A. Speed is a scalar quantity and velocity is a vector quantity.
Explanation:
A scalar quantity is one that consists of only a numerical value.
Speed is a scalar quantity because only the instantaneous value is indicated, for example the speedometer of a car that tells you your speed at the moment but not where you are going or in what direction are you going.
On the other hand, velocity is a vector quantity. Because it is composed of a <u>magnitude and a direction</u>, for example 10m/s to the south is a velocity, and 10m/s is a speed.
♥ If the wind is strong enough it can do so.
♥ By having a strong enough wind you can blow out the fire before the flame can consume any more vapor.
♥ If the wind is fast enough, like a birthday cake candle for example, the wind will burn out.
Answer:
C) Use two batteries instead of one.
Explanation:
-Strength of an electromagnet depends on the electrical current which flows through the wires.
-Two batteries have a higher current than one and thus higher strength in the electromagnet.
Answer:
t=18s
Explanation:
The final position of an object moving at constant speed is given by the formula 
, where 
is its initial position, v its speed and t the time elapsed.
For the cheetah we have 
, and for the gazelle 
. We want to know at which t their positions are equal, that is, 
, which means,
Where we can do:
We then substitute the values we have (the initial position of the cheetah is 0m), writing the meters in km so distance units cancel out correctly:
On the last step we just multiply by 3600 because is the number of seconds in an hour.
