a toy spring gun is used to shoot 28-g bullets vertically upward. the un deformed length is 150 mm, it is compressed to a length of 25 mm when the gun is ready to be shoot and expands to a length of 75mm as the bullet leaves the gun. a force of 45 N is required to maintain the spring in firing position when the length of the spring is 25mm. determine the velocity of the bullet as leaves the gun and the maximum height reached by a bullet