Answer:
Friction force is independent of the direction of the contacting surfaces
Explanation:
It can go any way depending on how much force is being out on it.
The inner planets are not colder or larger than the outer ones,
and they're not comprised of gas.
The inner planets are the ones that are made of rock. ( D ).
Answer:
The wavelength in vacuum is equal to 428.8 nm.
Explanation:
Given that,
The wavelength of light, 
The refractive index of glass, n = 1.51
We need to find the wavelength in vacuum. The relation between wavelength and refractive index is given by :

So, the wavelength in vacuum is equal to 428.8 nm.
This question is incomplete; here is the complete question:
Marco is conducting an experiment. He knows the wave that he is working with has a wavelength of 32.4 cm. If he measures the frequency as 3 hertz, which statement about the wave is accurate?
A. The wave has traveled 32.4 cm in 3 seconds.
B. The wave has traveled 32.4 cm in 9 seconds.
C. The wave has traveled 97.2 cm in 3 seconds.
D. The wave has traveled 97.2 cm in 1 second.
The answer to this question is D. The wave has traveled 97.2 cm in 1 second.
Explanation:
The frequency of a wave, which is in this case 3 hertz, represents the number of waves that go through a point during 1 second. According to this, if the frequency of the wave is 3 hertz this means in 1 second there were 3 waves. Moreover, if you multiply the wavelength (32.4cm) by the frequency (3) you will know the distance the wave traveled in 1 second: 32.4 x 3 = 97.2 cm. This makes option D the correct one as the distance in 1 second was 97.2 cm.
Answer:
Net displacement = 0
Distance traveled = 2PQ <_up and down
Explanation: