4. When a constant force acts on an object with a mass of 8 kg for a duration of 3 s. it increases the object's velocity from 4 m/s to 6 m/s . What is the magnitude of the applied force?
9. A tank filled partially with a liquid is subjected to a uniform horizontal acceleration. Which of the following is true for the surface of liquid in the tank?
Options
A. The liquid surface falls down on the direction of motion and rises up on the back side of the tank
B. The liquid surface falls down only at the center of the tank