Atoy friction car is propelled forward from rest by a girl's hand which causes it to reach a forward velocity of 3.5m/s in 0.4 seconds. it is then rreleased and later stops in 5.6 seconds

a)  Acceleration =

b) Slow down acceleration = 0.625

c) Car travels 9.8 m

Explanation:

  Acceleration = Change in velocity/Time

a) Change in velocity = 3.5-0 = 3.5 m/s

   Time = 0.4 seconds

    Acceleration =

b) Change in velocity = 0 - 3.5 = -3.5 m/s

   Time = 5.6 seconds

   Acceleration =

   Slow down acceleration = 0.625

c) We have equation of motion, , where u is the initial velocity, u is the final velocity, s is the displacement and a is the acceleration.

 Here v = 0 m/s, u = 3.5 m/s, a = -0.625

 Substituting

  So, car travels 9.8 m

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