1. What net force does the road exert on an 80 kg bike and rider to give them an acceleration of 3.2 m/s2? What would be the nature, or cause, of that force?

2. A 1600 kg car accelerates uniformly from 40 km/hr to 80 km/hr in 10.0 sec. What was the net force exerted on that car?

Please explain in detail.