Answer:
5 neutrons
Explanation:
Both protons and neutrons have a mass of about 1 atomic mass unit (amu). The number in the notation for an isotope is its mass in amu. That means the number is essentially the sum of protons and neutrons in the isotope (electrons don't contribute significantly to the mass).
If lithium has 3 protons, lithium-8 has 8 - 3 = 5 neutrons.
 
        
                    
             
        
        
        
Answer:
Force will be 7.97 N
Explanation:
We have given that earth is at s distance of 42000 km from the earth center 
So r = 42000 km = 42000000 m 
Mass m = 1500 kg 
Angular velocity of earth 
We have to find the force 
We know that force is given by 

 
        
             
        
        
        
Wavelength increases as Frequency decreases and vice versa.
This is because Wavelength and frequency are inversely related.
 
        
             
        
        
        
Answer:
x = 1474.9 [m]
Explanation:
To solve this problem we must use Newton's second law, which tells us that the sum of forces must be equal to the product of mass by acceleration.
We must understand that when forces are applied on the body, they tend to slow the body down to stop it.
So as the body continues to move to the left, it is slowing down. Therefore we must calculate this deceleration value using Newton's second law. We must perform a sum of forces on the x-axis equal to the product of mass by acceleration. With leftward movement as negative and rightward forces as positive.
ΣF = m*a
![10 +12*sin(60)= - 6*a\\a = - 3.39[m/s^{2}]](https://tex.z-dn.net/?f=10%20%2B12%2Asin%2860%29%3D%20-%206%2Aa%5C%5Ca%20%3D%20-%203.39%5Bm%2Fs%5E%7B2%7D%5D)
Now using the following equation of kinematics, we can calculate the distance of the block, before stopping completely. The initial speed must be 100 [m/s].

where:
Vf = final velocity = 0 (the block stops)
Vo = initial velocity = 100 [m/s]
a = - 3.39 [m/s²]
x = displacement [m]
![0 = 100^{2}-2*3.39*x\\x=\frac{10000}{2*3.39}\\x=1474.9[m]](https://tex.z-dn.net/?f=0%20%3D%20100%5E%7B2%7D-2%2A3.39%2Ax%5C%5Cx%3D%5Cfrac%7B10000%7D%7B2%2A3.39%7D%5C%5Cx%3D1474.9%5Bm%5D)
 
        
             
        
        
        
Answer: wavelength=velocity×period
Explanation:the relation between velocity, wavelength and period is
Wavelength=velocity×period