What must be true about projectiles? (Select all that are correct) a. The vertical velocity changes by -9.8 m/s every second

b. The horizontal acceleration is 9.8 m/s/s

c. any object in the air is considered a projectile

d. The horizontal and vertical components are independent of each other

e. There is no acceleration in the horizontal

At 20∘c, the hole in an aluminum ring is 2.800 cm in diameter. you need to slip this ring over a steel shaft that has a room-temperature diameter of 2.804 cm . 1. to what common temperature should the ring and the shaft be heated so that the ring will just fit onto the shaft? coefficients of linear thermal expansion of steel and aluminum are 12×10−6 k−1 and23×10−6 k−1 respectively.