Answer:
Friction     100 j
Explanation:
Friction causes the inequality between PE and KE 
100 J 
 
        
             
        
        
        
Answer:
1. Recollapsing universe
2. Critical universe
3. Coasting universe
Explanation:
Recollapsing universe has dark matter density greater than critical density. While critical universe has its matter density equal to the critical sensity. Coasting universe on the other hand has much smaller matter density compared to critical density.
Note that the critical density is approximately 10^-20 grams/cm3
 
        
             
        
        
        
Answer:
Explanation: Having two separate pathways of reaction and learning from pain is crucial to our survival. ... Therefore, humans tend to avoid objects or events that would cause them pain or harm; thus, adding this to their survival advantages.
 
        
             
        
        
        
C. Radiation           Hope this helps and You're welcome. :3