How much force would you need to cause a 20 kilogram object to accelerate in a straight line to 20 meter per second? if you answer/answered, you a ton with my physics homework : )

Water is siphoned from a large tank and discharges into the atmosphere through a 50-mm diameter tube. the end of the tube is b = 2.1 m below the tank bottom which is a = 7.4 m deep, and viscous effects are negligible. determine the maximum height h over which the water can be siphoned without cavitation occurring. atmospheric pressure is 101.4 kpa, and the water vapor pressure is 1.79 kpa (absolute)

What is the weight of a feather (mass = 0.0001 kg) that floats through earth's and the moon's atmospheres?

The friction of the water on a boat produces an acceleration of -10. m/s2. if the boat is traveling at 30. m/s and the motor is shut off, how long it take the boat to slow down to 5.0 m/s?