-- The acceleration of gravity is 9.8 m/s².
So if there's no air resistance, the speed of a falling object 
always increases by 9.8 m/s for every second it falls.
             Speed  =  (original speed) + (gravity  x  falling time)
-- If it has no vertical speed when it started, then at the end
of 3 seconds, its speed is
                         =       (0)            + (9.8 m/s²  x  3 sec)
                       Velocity  =  29.4 m/s downward .  
        
             
        
        
        
To answer that question, we don't care what the highest and lowest 
levels of the wave are, or how far apart they are.  We only need to be 
able to identify the highest point on the wave, and keep track of how 
often those pass by us.
You said it takes 4 seconds for a complete wave to pass by.
Through the sheer power of intellect, I'm able to take that information
and calculate that  1/4  of the wave passes by in 1 second.
There's your frequency . . .  1/4 per second, or  0.25 Hz.
        
             
        
        
        
Answer:
a = 3.27 m/s²
v = 2.56 m/s
Explanation:
given,
mass A = 1 kg
mass B = 2 kg
vertical distance between them = 1 m










a = 3.27 m/s²
The speed of the system at that moment is:
v² = u² + 2×a×s
v² = 0² + 2× 3.27 × 1 
v ² = 6.54
v = 2.56 m/s
 
        
             
        
        
        
Answer:

Explanation:
From the question we are told that:
Radius 
Charge Density 
Distance  
Generally the equation for electric field is mathematically given by



 
        
             
        
        
        
No spacecraft has been built yet that was able to absorb harmful 
radiations in space, change weather conditions on Earth, or destroy 
meteors and comets which might strike Earth.
We should continue to send robotic spacecrafts into space 
because they help discard some myths about objects in space.  
In other words, they help us learn things that we never knew before.