There could be more than just one answer, since kilograms can be converted to grams, to miligrams, etc.

or

Why?
Let's remember some conversion factors to work with kilograms (kg)

So, we are given the momentum:

We can rewrite the units of the momentum (equivalent) as follow:

and

Note: There could be more equivalent units for the momentum, in example, we could work with equivalent units for meters (distance) and seconds (time).
Have a nice day!
Typebars
Turbocars
Teacups
Teapoys
Tourneys
Toecaps
Trepangs
Tabourers
Trouncers
Troupers
Terraces
Trances
Turbans
Toupees
Toucans
Sorry if this is not what you want me to do and I just threw a bunch of words at you.
The answer is B.
t = Vy / g
t =( 19 x sin21 ) / 9.8 = 0.69s
I don't know the answer but I do know this
A mantle plume is posited to exist where hot rock nucleates at the core-mantle boundary and rises through the Earth's mantle becoming a diapir in the Earth's crust.[3] The currently active volcanic centers are known as "hot spots". In particular, the concept that mantle plumes are fixed relative to one another, and anchored at the core-mantle boundary, was thought to provide a natural explanation for the time-progressive chains of older volcanoes seen extending out from some such hot spots, such as the Hawaiian–Emperor seamount chain.