A 20-kg crate is sitting on a frictionless ice rink. A child standing at the side of the ice rink uses a slingshot to launch a 1. 5-kg beanbag at the crate. Assume that the beanbag strikes the crate horizontally in the +x direction with a speed of 10 m/s. The beanbag bounces straight back in the -x direction with a speed of 6 m/s. Using conservation of momentum, calculate the speed of the crate after the beanbag hits it.