Answer:
a) 30 degree
Explanation:
As we know that time of flight of the projectile depends on the the vertical component of the velocity always
It is given as

now we know that

so we will have

since we know that two projectiles are projected at same speed but different angles
so smaller the angle will take smaller time
so it would be 30 degree projectile which will take smaller time
Answer:
The rotor's angular velocity is 82.73rad/s
Explanation:
It is a curvilinear movement of a constant radius. If there is uniform angular acceleration, then it is a circular motion with constant acceleration, whose equations are analogous to that of the translational motion.
Calculating the initial velocity of the rotor, V1 in rad/s
V1 = 610rev/minute × 6.28 × 1miute/60secs
V1 = 63.85rad/s
Using kinematic equation to calculate the final velocity of the rotor
Given:
Angular acceleration = 5.9rad/s^2
Time,t= 3.2seconds
V2 = V1 + a × t
V2 = 63.85 + (5.9)× (3.2)
V2 = 63.85 + 18.88
V2 = 82.73rads/s