What's the acceleration if you push with a 20N horizontal force on a 3 kg block on a horizontal friction-free air table?

If I want to lift a 2.0-kg object into the air with a rope, such that the object accelerates upward at a rate of 3.0 m/s2, what size force upward do I need to apply to the rope?  (Hint: the mass will be used in more than one formula.)

If the force of the fan pushes the air backward with 150 N, what is the forward force of the air on the boat? If the mass of the boat is 220 kg, and you ignore friction between the boat and the water, find how far the boat will travel in the first minute. G: ff=150N  mass=220kg  U:  acceleration  E: a=f/m S: a=150N220kg S: the forward force of air on the boat is 0.68m/s2   =v1△+ 12 a (△t)2 =0+12 (0.68m/s2)(60)2 1227.273m is how far the boat traveled in 1 minute

A 70 kg bicyclist is riding her 15 kg bicycle downhill on a road with a slope of 80without pedaling or braking. The bicyclist has a frontal area of 0.45 m2and a dragcoefficient of 1.1 in the upright position, and a frontal area of 0.4 m2and a dragcoefficient of 0.9 in a racing position. If the downhill speed of the bicyclist(terminal velocity) can be determined when the total force acting on the “body” inthe direction of movement is equal to zero, determine the percentage of downspeed that she can be increased when she is in a racing position. Air temperatureis 150C and disregarding the rolling resistance and friction at the bearing.