What would be the effect if a meteorite the size of a football stadium

A.) Hit land, say, right outside of Oklahoma City.

B.) Hit water, say in the middle of the Gulf or Mexico

Not near enough data to supply a good answer --
1. what's the ojbect's density?
2. what's its mass?
3. what's its angle of impact?
4. what's its composition?

Teacher needs to get his/her act together...!

You can try some different parameters at this website =>http://www.purdue.edu/impactearth

a, depends on speed/ angle of entry = 1/2 mile crater possibly

-- heat blast/ shockwave/ mini hiroshima bomb without nuclear fallout.

b, same thing... + a tsunami wave that could do damage along coastlines in gulf.

http://simulator.down2earth.eu/
heres a simulator