A 8 kg object going 4 m/s ends up going 36 m/s in 6 seconds. What is the force on the object.

1 N is defined by (1kg accelerated 1m/s²)

 

8 kg accelerated 32m/6s² or 32/16m/s² or 5.333333m/s²

 

8xs the weight and 5.333333xs the acceleration should require (8 * 5.333333)xs the force.

It should take about 42.666667 Newtons of force.