Volumetric cylinders and volumetric flasks
a) 1.48 m/s
The tuning fork is moving by simple harmonic motion: so, the maximum speed of the tip of the prong is related to the frequency and the amplitude by

where
is the maximum speed
is the angular frequency
A is the amplitude
For the tuning fork in the problem, we have
, where f is the frequency
is the amplitude
Therefore, the maximum speed is

b) 
The fly's maximum kinetic energy is given by

where
is the mass of the fly
is the maximum speed
Substituting into the equation, we find

The turn signal indicator should be activated at least FIVE SECONDS before merging. This is done in order to let the other drivers behind you know that you want to turn and to slow down for you, this keeps you and other road users safe and prevent accident.
·The acceleration of gravity is proportional to
1 / (the square of the distance from the center) .
When we're on the surface, we're 1 radius from the center of the Earth,
and the acceleration of gravity is 9.8 m/s² .
The boy's weight = (mass) · (gravity) = (50kg) · (9.8 m/s²)
= 490 newtons .
At the distance of 5 radii from the center (4 radii altitude from the surface),
the acceleration of gravity is
(9.8 m/s²) · (1/5)² = 0.39 m/s² .
The boy's weight is (mass) · (gravity) = (50kg) · (0.39 m/s²)
= 19.6 newtons .
Just as we expected, his weight at that distance is
(19.6 / 490) = 0.04 = 1/25 = 1/5² of his weight on the surface.