9. An object moving at a constant velocity accelerates at a constant rate of 20 m/s for a distance of 100 m. At the end of the acceleration the object has a velocity of 80 m/s. What was its velocity
before accelerating?

I believe the answer is roughly 49m/s

Explanation:

List all given variables:

Accel=20m/s^2

Dist=100m

Final velocity=80m/s

Initial velocity=?

Using the equation i=sqrt(f^2-2a*d) where i =initial velocity, f=final velocity, a=acceleration, and d=distance, we can plug in the known values and solve for initial velocity

i=sqrt(80^2-2*20*100)

i=sqrt(6400-4000)

i=sqrt(2400)

i=48.99, rounded up to 49m/s as the initial velocity

This is my speculation about this answer would appreciate if anyone can confirm this.

no simpler subs form complex ones. synthesise = make

see the picture for the vector

the magnitude of the vector by pythagorean theorem

r = √( (-10)^2 + (3)^2 ) = √109

magnitude = √109 units

the direction angle between vector and x-axis is

tan^(-1)(3/10) = 16.699

so the direction is approximately 16.7 degrees north of west