Answer:
n.6 is T 
Explanation:
because mass always stays the same where ever you are but weight changes depending on the gravity 
 
        
                    
             
        
        
        
Answer:
False
Explanation:
All the lanthanides are not radioactive in nature. Just one of the lanthanides are radioactive. 
- The lanthanides belong to the f-block on the periodic table
- Only Promethium in this group are radioactive in nature. 
- Other elements in the lanthanide series might have radioactive isotopes. 
 
        
             
        
        
        
Answer:
 14 N 
Explanation:
The tension in the second string is puling both the masses of 20 kg and 8 kg with acceleration of 0.5 m s⁻²
So tension in the second string = total mass x acceleration 
= 28 x .5 = 14 N . Ans.. 
 
        
             
        
        
        
Explanation:
Given that,
Initial speed of a car, u = 12 m/s
Aceleration, a = -1.6 m/s²
(a) The displacement of car after 6 seconds is :

(b) The displacement of the car after 9 seconds is :

Hence, this is the required solution.
 
        
             
        
        
        
Answer: elastic potential energy = 20.27 J
Explanation:
Given that the 
Mass M = 0.470 kg
Height h = 4.40 m
Spring constant K = 85 N/m
The maximum elastic potential will be equal to the maximum kinetic energy experienced by the block. 
But according to conservative of energy, the maximum kinetic energy is equal to the maximum potential energy experienced by the block of mass M.
That is 
K .E = P.E = mgh
Where g = 9.8m/s^2
Substitutes all the parameters into the formula 
K.E = 0.470 × 9.8 × 4.4
K.E = 20.27 J
Where K.E = maximum elastic potential energy stored in the spring during the motion of the blocks after the collision which is 20.27J.