Answer:
Explanation:
Given
time taken 
Speed acquired in 2 sec 
Here initial velocity is zero 
acceleration is the rate of change of velocity in a given time


Distance travel in this time 

where  
s=displacement
u=initial velocity
a=acceleration
t=time


so Jet Plane travels a distance of 42 m in 2 s                                 
 
        
             
        
        
        
That would be a the first law of newton's laws of motion because it stops from an external force
 
        
             
        
        
        
Answer:
10 gram gold is added 
Explanation:
given data 
pure gold = (24/24)
added = 15 grams
gold = 14 K  ( 14/24)
gold = 18 K ( 18/24)
to find out
How much pure gold added
solution
we know here that when we add gold to get 20 K gold or 22K
so we added here 15 gram 14 K 
we consider here m is pure gold added
so by composition here 
we get
15 (14K)  + m ( 24 K) = ( 15 + m ) (18)    ...................1
solve it and find m 
m = 10 
so 10 gram gold is added 
 
        
             
        
        
        
Answer:(a) 50 N
(b)38.34 N
Explanation:
Given
Maximum tension(T) in line 50 N
(a)If line is moving up with constant velocity i.e. there is no acceleration
This will happen when Tension is equal to weight of Fish
T-mg=0
T=mg
Maximum weight in this case will be 50 N
(b)acceleration of magnitude 
T-mg=ma


m=3.91
Therefore weight is 