Answer:
21
Explanation: its actually 20.85 but i guess they round to 21
By what i know i think that the answer would be A a homogeneous mixture.
Answer:
The range of wavelengths of the sound is 7692.30 m and 3846.15 m
Explanation:
A bat emits pulses of sound at a frequency between 39 kHz and 78 kHz. It is required to find the range of wavelengths of this sound.
Bat uses ultrasonic waves. It moves with the speed of light.
If f = 39 kHz,

If f = 78 kHz,

So, the range of wavelengths of the sound is 7692.30 m and 3846.15 m.
Answer:
60 N.C
Explanation:
The box will move in the direction of the push and pull with a force of 60 N. C.