Which is the best example of an unbalanced force? A)A book resting on a shelf
b)A train accelerating from the station.
c) A chair sitting motionless
d) a car driving at a constant speed.
plz answer correctly

It has to be c or a because no force is being made in these to.

the correct answer should be c

Answer: it will take   4.36 seconds to reach her average velocity 10.69 miles/hour.explanation:   we have equation of motion ,where s is the displacement, a is the acceleration, u is the initial velocity and t is the time taken.average velocity = displacement/ time taken.average velocity = 10.69 miles/hr = 10.69*1.6*1000/(60*60) = 4.75 m/s4.75 = s/ts = 4. 1we also have acceleration = 2.18 m/s², initial velocity = 0 m/sso it will take   4.36 seconds to reach her average velocity 10.69 miles/hour.

Answer:   [a]:   "slate" .