Answer:
ΔF=125.22 %
Explanation:
We know that drag force on the car given as

=Drag coefficient
A=Projected area
v=Velocity
ρ=Density
All other quantity are constant so we can say that drag force and velocity can be given as

Now by putting the values



Percentage Change in the drag force



ΔF=125.22 %
Therefore force will increase by 125.22 %.
Answer:
<u>40 m/s</u>
Explanation:
The final velocity of an object that experiences a period of acceleration is given by:
v - vi = A*t
Initial velocity, vi, is = 20m/s
Acceleration, A, is 4m/2^2
Time, t, is 5 seconds
v - vi = A*t
v - 20m/s = (4m/2^2)/(5 sec)
v = (20 m/s) + (20 m/s)
v = 40 m/s
It would be kinetic energy. Let's say the book is weighs 10 Newtons you need to use a force of 10 Newtons to lift the book. In other words it's positive. As you move the book you're giving it energy. Namely potential energy which will turn to kinetic energy if you let it go. So you're changing it's position and energy.