While skateboarding at 19 km/h, alana throws a tennis ball at 11 km/h to her friend oliver. if alana is the reference frame, the speed of the tennis ball is
(blank)
km/h.

explanation:

a fuel engine ( known as a gasoline engine in american english )is an internal combustion engine with spark ignition, designed to run on petrol (gasoline) and similar volatile fuels.

the simple machine has three main features. they are:

fulcrum is the center point or pivot point of the machine. effort is input force/ applied force. load is external force/ output.

the keisha 's machine labels are

x : load

y: fulcrum

z: lever