Explanation:
When a constant force acts upon an object the acceleration of the object varies inversely with its mass.

or

If m₁ = 21 kg, a₁ = 3 m/s², m₂ = 9 kg
We need to find a₂
So,

So, if mass is 9 kg, its acceleration is 7 m/s².
You have to have electrons that are in the materials conduction band. Then you apply a voltage across the material.
Answer:
A
Explanation:
warm air rises creating low presure
cold air sinks creating high presure
so this means that temprature is realated to presure.
It is possible to demonstrate that the maximum distance occurs when the angle at which the projectile is fired is

.
In fact, the laws of motions on both x- and y- directions are


From the second equation, we get the time t at which the projectile hits the ground, by requiring

, and we get:

And inserting this value into Sx(t), we find

And this value is maximum when

, so this is the angle at which the projectile reaches its maximum distance.
So now we can take again the law of motion on the x-axis

And by using

, we find the value of the initial velocity v0: