ElectricPavlov

Acceleration is change in velocity divided by change in time

(15 m/s-35 m/s) / 4 s = -5 m/s²

v=at

7850 m/s = 29 m/s²   *t                 solve for t=270.7 sec

you are given   m    and  h      and you want  m/h    just divide  m/h     3/5 m  /  1/4 h

As you look at the graph from L to right....what range of x does it appear to be going 'downhill' ?  

   From -2 to 0.5

Since it is symmetrical parabola, the high point will be directly above the distance between the zeroes (approx   0 and 4)....   2 seconds (which you can actually SEE just by looking at the graph)

sin(α + β) = sin(α) cos(β) + cos(α) sin(β)

All THREE  of the angles of a triangle sum to 180^o

x = base angle

40 + x + x  = 180

x = 70^o

The last one:   the two angles encompass the entire circle 360⁰

    ^{remember, inscribed angles in a circle intercept arcs TWICE their measure}

^{2 * (2x  + 4x+24)  = 360}

^{x = 26}

^{sooo     EFC =4x +24 = 4*26   + 24 =    128 degrees}

Assumming this is a triangle....there are 180^o  in a triangle....alll of the angles have to sum to 180

7x-27 + 9x-34 + 9x-34 = 180

25x -95 =180

x=11

Base is  9x-34   = 9(11)-34 =65^o

C.  Total area of wheel = pi * r^2     (be aware...you are given DIAMETER 24"    r = 12" )

         Fraction of total area represented by ABC  is 40/360

               so area is   pi * 12²  * 40/360 = ~ 50 in²