A boiling pot of water (the water travels in a current throughout the pot), a hot air balloon (hot air rises, making the balloon rise) , and cup of a steaming, hot liquid (hot air rises, creating steam) are all situations where convection occurs.
Answer:
The magnification of an astronomical telescope is -30.83.
Explanation:
The expression for the magnification of an astronomical telescope is as follows;

Here, M is the magnification of an astronomical telescope,
is the focal length of the eyepiece lens and
is the focal length of the objective lens.
It is given in the problem that an astronomical telescope having a focal length of objective lens 74 cm and whose eyepiece has a focal length of 2.4 cm.
Put
and
in the above expression.

M=-30.83
Therefore, the magnification of an astronomical telescope is -30.83.
Answer:
1.58 Hz
Explanation:
The frequency of the simple pendulum is given by
f = 1/T
= 1/2π√g/l
In this problem, I = 10.0 cm = 0.1 m
f = 1/2π√9.8/0.1
= 1.58 Hz
Answer:
2 Joules
Explanation:
Kinetic Energy = 1/2 of (Mass x Velocity^2)
There's a short handy formula for that.
If the object is just dropped and not tossed, and it's not affected by air resistance on the way down, then the distance it falls in T seconds is
D = (1/2) (gravity) (T²)
For this problem . . .
176.4 m = (1/2) (9.8 m/s²) (T²)
Divide each side by (4.9 m/s²) :
T² = (176.4 m) / (4.9 m/s²)
T² = (36 s²)
Take the square root of each side:
<em>T = 6 seconds</em>