Question

Please help me with physics ks3!! Sound waves and hearding (pic incl)

Answer 1

Your answers for a), b), and c) are correct.  Good work !

d). The high noise levels in Technology and PE are more of
a concern to the teachers than to the students because the
students are only in there for 1 or 2 periods a day, but the
Technology and PE teachers are in there ALL day.

e).  Mr. Jones can't hear as high frequency as Jenny can because
he is much older than Jenny is.  Sadly, even without damage due to
loud noise, the ability to hear high frequencies does decrease with age.

f).  The wooden surfaces in the gym cause the gym to be louder
than it would be if it had carpet on the floor.  Carpet ... and soft
walls and ceilings ... absorb a lot of the sound that hits them. 
But hard surfaces don't absorb much of the sound that hits them,
so it just keeps bouncing around until it finally fades away. 

You can see this easily ... just go into the gym at your school, clap
your hands once, and notice how long you keep hearing the sound
after you clap. 

Answer 2

DB are units that might be good to add. 
They are louder as they use loud equipment or have practicals in which students talk.
It's more of a risk for teachers as they are exposed to it for every lesson they teach as students might only have one hour of it each day.
More likely reason is he's older so the level of pitch detection decreases with age.
f) the noise is reflected off the smooth surfaces and echoes