A Particle Moving with a Constant Acceleration Has a Velocity

Multiple Choice

A particle moving with a constant acceleration has a velocity of 20 cm/s when its position is x = 10 cm. Its position 7.0 s later is x = -30 cm. What is the acceleration of the particle?

A) (-7.3 cm/s2)
B) (-8.9 cm/s2)
C) (-11 cm/s2)
D) (-15 cm/s2)
E) (-13 cm/s2)