Answer:
Explanation:
Given
inclination 
initial speed 
Point of release is 45 m above the ground
Considering stone to be a projectile, so time taken by projectile for its zero vertical displacement is 



Now after completing zero vertical displacement , stone needs to travel another 45 m in downward direction with initial speed u=20\sin 30

where, 






thus total time time required is 
vertical velocity just before hitting



Horizontal velocity 
Net velocity Just before hitting 


                   
 
        
             
        
        
        
Given that,
Mass of each washer  = 4.9 g
We need to calculate the mass of two washers in kg
Using conversion of unit
Mass of each washer 
So, Mass of two washers is

Put the value of m


If 4 washer are attached to the spring 
We need to calculate the applied force on the car 
Using formula of force

Put the value into the formula


Hence, (i), The mass of two washers is 0.0098 kg.
(ii). The applied force on the car is 0.192 N.
 
        
             
        
        
        
Answer:
a. 900 J
b. 0.383
Explanation:
According to the question, the given data is as follows
 Horizontal force = 150 N
Packing crate = 40.0 kg
Distance = 6.00 m
Based on the above information
a. The work done by the 150-N force is 


= 900 J
b. Now the coefficient of kinetic friction between the crate and surface is 


= .383
We simply applied the above formulas so that each one part could calculate 
 
        
             
        
        
        
Answer:
The correct answer is:
False
Explanation:
Nuclear fission is the splitting of nucleus of an atom which results in the emission of high amount of energy.
<u>Example:</u>
Heavy atom (i.e. uranium) when bombarded with neutrons, its nucleus split into smaller lighter weight nuclei and release a huge amount of energy. (Nuclear fission also takes place without neutrons i.e. in the form of radioactive decay (the process in which an unstable nucleus of an atom releases energy in the form of radiation)).
 
        
             
        
        
        
Yes but they not supposed to