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:
correct
Explanation:
the atomic number is located top left of the atomic symbol given
A mixed cost contains a variable element and a fixed element.
Option a
<u>Explanation:</u>
Mixed costs are those costs that has both variable and fixed component. Example: operating cost of a machinery includes fixed costs that cannot be changed with other variable costs like fuel, insurance, depreciation, etc.
It is also named as semi-variable costs. And the formula to calculate mixed cost is as follows,

where,
- y is the "total cost
"
- a is the "fixed cost per period"
- b is the "variable rate per unit of activity"
- x is the "number of units of activity"
Answer:
<h3> 3.057m</h3>
Explanation:
According to law of gravitation;
F = GMm/d²
G is the universal gravitation
M and m are the masses
d is the distance between the masses
d² = GMm/F
d² = 6.67408 × 10-11 *3000*7000/0.0015
d² = 140.15568*10^-5/0.0015
d² = 1.4016*10^-3/0.0015
d² = 1.4016*10^-3/1.5*10^-3
d² = 0.9344*10
d² = 9.344
d = √9.344
d = 3.057m
Hence the distance between the two objects is 3.057m
First we write the corresponding kinematics equations:
a = -g
v = -g * t + vo
y = -g * ((t ^ 2) / 2) + vo * t + yo
Substituting the values:
y = - (9.81) * (((0.50) ^ 2) / 2) + (19) * (0.50) + (0) = 8.27m
answer:
the displacement at the time of 0.50s is 8.27m