Unlike a ball, an atom doesn't have a fixed radius. The radius of an atom can only be found by measuring the distance between the nuclei of two touching atoms, and then halving that distance... Does that answer your question?
        
             
        
        
        
We use the following expression
T = 2*pi *sqrt(l/g)
Where T is the period of the pendulum
l is the length of the pendulum
and g the acceleration of gravity
We solve for l
l = [T/2*pi]² *g = [30s/2*pi]²* 9.8 [m/s²] = 223.413 m
The tower would need to be at least 223.413 m high
        
             
        
        
        
Answer:
The potential energy of the more massive one is twice that of the other.
Explanation:
Potential energy is given by
<em>PE</em> = <em>mgh</em>
where <em>m</em> = mass of body, <em>g</em> = acceleration of gravity and <em>h</em> = height or elevation.
For the less massive car, let the mass be  . Then its <em>PE</em> is
. Then its <em>PE</em> is

For the massive car, let the mass be  .  Its <em>PE</em> is
.  Its <em>PE</em> is

But 

Hence, the potential energy of the more massive one is twice that of the other.
 
        
             
        
        
        
A plant collects sunlight to form glucose, and your friend proposes an idea for a fan. Conserved = saving
        
                    
             
        
        
        
In this item, we let x be the rate of the boat in still water and y be the rate of the current.
Upstream. When the boat is going upstream, the speed in still water is deducted by the speed of the current because the boat goes against the water. The distance covered is calculated by multiplying the number of hours and the speed.
                 (x - y)(3) = 144
Downstream. The speed of the boat going downstream is equal to x + y because the boat goes with the current.
                (x + y)(2) = 144
The system of linear equations we can use to solve for x is,
                  3x - 3y  = 144
                  2x + 2y = 144
We use either elimination or substitution.
 
We solve for the y of the first equation in terms of x,
                   y =  -(144 - 3x)/3
Substitute this to the second equation,
            2x + 2(-1)(144 - 3x)/3 = 144
The value of x from the equation is 60
<em>ANSWER: 60 km/h</em>