Question 4 Of the various methods used to measure the rate of fire of projectiles, the most known is the ballistic pendulum, represented by the animation below. In this method, a projectile is fired next to a block that is: * consists of a soft material to the point that the projectile can penetrate it; * thick enough that the design, when penetrating it, does not come out through the other side; * heavy so as not to gain too much speed when incorporating the projectile. The block is attached to the ceiling and begins to oscillate like a pendulum after incorporating the projectile raised. The person wishing to determine the rate of fire of the projectile seeks accurately measure how much the block rises (measure indicated by h) after incorporating the projectile. PENDULUM ballistic Let's say the 1796.0 g Block was used in a ballistic pendulum to measure the firing speed of a 4.0 g projectile inherent in a new model of revolver. O block used satisfied all the conditions presented above and Rose a height h = 20 CT. Considering the acceleration of gravity equal to 10 m/s2 and that the air does not produce significant interference, use the theories of mechanics to determine which firing speed of this projectile