Answer:

Explanation:
Given that,
Force, F = 52 N
Mass of the block, m = 4 kg
We need to find the acceleration of the object. We know that,
F = ma
Put the values,

So, the acceleration of the object is equal to
.
The question is not well presented.
There is ______ shift in sound frequency for observers towards whom the source is approaching.
Answer:
The gap should be filled with an apparent upward
Explanation:
The Doppler effect (also referred to as the Doppler shift) is the difference in frequency of a wave when related to an observer who has a relative movement to the wave source
The Doppler effect can be observed to occur with all types of waves - most notably water waves, sound waves, and light waves
The Doppler effect describes sound as an effect which is produced from a moving source of wave.
According to the Doppler effect;
When the source of waves in which there is an apparent upward shift in frequency for observers towards whom the source is approaching.
20 cm = bright
40 cm = dim
The longer the wire the bigger the resistance
Objects have the same velocity only if they are moving at the same speed and in the same direction. Objects moving at different speeds, in different directions, or both have different velocities.
higher temp = higher energy = higher frequency = shorter wavelength