Answer: If the woodpecker drums upon a tree 5 times in one second, then the frequency is 5 Hz; each drum must endure for one-fifth a second, so the period is 0.2 s.
Answer:
Q (heat) = S * m * (T2 - T1) where Q is heat gained (loss), S the specific heat capacity of the substance and T2, T1 are the final and initial temps
Q = .215 cal / (g deg C) * 5 g * (20 - 80) deg C = -64.5 cal
Since the question specifies the heat emitted, then 64.5 cal is the
heat emitted (loss).
When you work out it helps clear your thoughts and think of nothing. It makes you feel good.
B- lack of control.
the scientists did not have a proper control group.