A railroad gun of mass M = 2.0 kg fires a shell of mass m =1.0 kg at an angle of theta= 35.0 with respect to the horizontal as measured relative to the gun. After the firing is complete, the final speed of the projectile relative to the gun (muzzle velocity) is v_0 =100.0 m/s . The gun recoils with speed v_r and the instant the projectile leaves the gun, it makes an angle phi with respect to the ground.

Question

A railroad gun of mass M = 2.0 kg fires a shell of mass m =1.0 kg at an angle of theta= 35.0 with respect to the horizontal as measured relative to the gun. After the firing is complete, the final speed of the projectile relative to the gun (muzzle velocity) is v_0 =100.0 m/s . The gun recoils with speed v_r and the instant the projectile leaves the gun, it makes an angle phi with respect to the ground. 
a)What is v_p , the speed of the projectile with respect to the ground? 
b)What is phi , the angle that the projectile makes with the horizontal with respect to the ground (in degrees)?