Answer:
Sound needs a material medium for their propagation like solid, liquid or gas to travel because the molecules of solid, liquid and gases carry sound waves from one point to another. Sound cannot progress through the vacuum because the vacuum has no molecules which can vibrate and carry the sound waves.
Answer:
a) 60 N
b) 860 N
Explanation:
Given that,
= 100 kg
= 20 kg
= 8.0 ![\frac{m}{s^{2}}](https://tex.z-dn.net/?f=%5Cfrac%7Bm%7D%7Bs%5E%7B2%7D%7D)
= 3.0 ![\frac{m}{s^{2}}](https://tex.z-dn.net/?f=%5Cfrac%7Bm%7D%7Bs%5E%7B2%7D%7D)
a) By Newton's Law,
∑![F_{m_2,x} = f_k = m_{2} * a_{2}](https://tex.z-dn.net/?f=F_%7Bm_2%2Cx%7D%20%3D%20f_k%20%3D%20m_%7B2%7D%20%2A%20a_%7B2%7D)
∑![F_{m_2,y} = F_{N} - m_{2} * g = 0](https://tex.z-dn.net/?f=F_%7Bm_2%2Cy%7D%20%3D%20F_%7BN%7D%20-%20m_%7B2%7D%20%2A%20g%20%3D%200)
Hence,
![f_k = m_2 * a_2 = 20 * 3 = 60 N](https://tex.z-dn.net/?f=f_k%20%3D%20m_2%20%2A%20a_2%20%3D%2020%20%2A%203%20%3D%2060%20N)
b) By Newton's Law
∑![F_{m_1,x} = F = m_{1} * a_{1}](https://tex.z-dn.net/?f=F_%7Bm_1%2Cx%7D%20%3D%20F%20%3D%20m_%7B1%7D%20%2A%20a_%7B1%7D)
Hence,
![F = m_{1} * a_{1} = 100 * 8 = 800 N](https://tex.z-dn.net/?f=F%20%3D%20m_%7B1%7D%20%2A%20a_%7B1%7D%20%3D%20100%20%2A%208%20%3D%20800%20N)
Net force acting on 100 kg mass,
![F_{net} = F + f_k = 800 + 60 = 860 N](https://tex.z-dn.net/?f=F_%7Bnet%7D%20%3D%20F%20%2B%20f_k%20%3D%20800%20%2B%2060%20%3D%20860%20N)
Answer:
they can blend in with their suroundings
Explanation:
Isotopes describes atoms with different atomic masses due to varying numbers of neutrons