-Velocity is the speed of any moving object in a given direction, whilst Speed is the rate of an object's ability to move.
-Velocity can change if the direction or time is changed, the basic equation of velocity is: v = d/t
v - velocity
d - distance
t - time
If one of these factors change, it affects the other.
Hope this answers the question!
Answer:
13 N
Explanation:
The Net Force of an object should be the difference between the forces applied to the object if the object is not in equilibrium. This object is not in equilibrium so therefore by finding the difference between the forces, you will find your answer. 20 N - 7 N = 13 N.
1) Acceleration: 
The motion of the plane is a uniformly accelerated motion, so we can find its acceleration by using the suvat equation

where
v is the final velocity
u is the initial velocity
a is the acceleration
s is the displacement
Here we have
v = 150 m/s is the final velocity of the plane
u = 0 (it starts from rest)
a=?
s = 1500 m is the displacement
Solving for a, we find

2. Time: 20 s
For this part of the problem, we can use another suvat equation:

v is the final velocity
u is the initial velocity
a is the acceleration
t is the time
Here we already know:
v = 150 m/s is the final velocity of the plane
u = 0 (it starts from rest)
(found in part 1)
Solving for t, we find the time taken for the plane to reach the final velocity of 150 m/s:

The height need to change by 4 to double the final velocity.
<h3>Final velocity of the object</h3>
The final velocity of an object during a free fall is related to maximum height of fall as given the equation below.
v = √2gh
v² = 2gh
v²/h = 2g
v₁²/h₁ = v₂²/h₂
when v₂ = 2v₁, change in height is calculated as;
h₂ = h₁v₂²/v₁²
h₂ = (h₁ (2v₁)²) / (v₁)²
h₂ = 4h₁v₁² / v₁²
h₂ = 4h₁
Thus, the height need to change by 4 to double the final velocity.
Learn more about final velocity here: brainly.com/question/25905661
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