In any case, your mass would be<em> 68 kg </em>no matter what
 
        
             
        
        
        
I think it 32, but i’m not sure
        
                    
             
        
        
        
Answer:
a) 
 
   
b) 

  
Explanation:
Searching the missed information we have:                                        
E: is the energy emitted in the plutonium decay = 8.40x10⁻¹³ J
m(⁴He): is the mass of the helium nucleus = 6.68x10⁻²⁷ kg  
m(²³⁵U): is the mass of the helium U-235 nucleus = 3.92x10⁻²⁵ kg            
a) We can find the velocities of the two nuclei by conservation of linear momentum and kinetic energy:
Linear momentum:


Since the plutonium nucleus is originally at rest,  :
:
 
  
 (1)
    (1)
Kinetic Energy: 

 
    
 (2)
   (2)     
By entering equation (1) into (2) we have:
 
  
 
   
Solving the above equation for  we have:
 we have:

And by entering that value into equation (1):
 
                         
The minus sign means that the helium-4 nucleus is moving in the opposite direction to the uranium-235 nucleus.
b) Now, the kinetic energy of each nucleus is:
For He-4:

For U-235:

  
I hope it helps you!                                                                                    
 
        
             
        
        
        
Kepler's laws were enunciated to model in a mathematical way the movement of the planets in their respective orbits around the Sun.
 There are three laws of Kepler.
 In particular, Kepler's first law states the following:
 "All the planets move around the Sun describing elliptical orbits, the Sun is in one of the foci of the ellipse."
 Answer:
 Kepler's 1st law of planetary motion states that the planets have an elliptical orbit, with the Sun at one focal point of the ellipse.
 a. 1st law