For the system of connected bodies shown below, determine the acceleration of the system if there exists a coefficient of friction of mu = 0.2 m_{2} = 10kg and m_{1} = 3m_{2} (Take g= 9.8m /s^2)

Question 2: 

A cannon located on the ground fires a projectile with a launch angle of 30 degrees. The initial speed of the bullet is 1800 km/h. How long was the projectile in the air? What is the maximum height reached? What is the position of the projectile when two-thirds of the total time in the air has elapsed? Take g = 9.8m/(s^2)

 

m m m m