It would take roughly 3 seconds.
        
             
        
        
        
Answer:
60 boxes
Explanation:
The work done by lifting a single box is equal to the force applied (the weight of the box) times the displacement of the box:

Power is related to the work done by the equation:

where W is the work done and t is the time. In this problem, we are told that the power used is P=60.0 W, while the time taken is t = 1 min = 60 s, so the total work done must be

Therefore, the number of boxes that she has to lift in order to use this power is the total work divided by the work done in lifting each box:

 
        
             
        
        
        
Answer: A river delta is a landform created by deposition of sediment that is carried by a river as the flow leaves its mouth and enters slower-moving or stagnant water. This occurs when a river enters an ocean, sea, estuary, lake, reservoir, or (more rarely) another river that cannot carry away the supplied sediment. The size and shape of a delta is controlled by the balance between watershed processes that supply sediment.
 
        
             
        
        
        
Answer:
The momentum is 1.94 kg m/s.
Explanation:
To solve this problem we equate the potential energy of the spring with the kinetic energy of the ball.
The potential energy  of the compressed spring is given by
 of the compressed spring is given by
 ,
,
where  is the length of compression and
 is the length of compression and  is the spring constant.
 is the spring constant. 
And the kinetic energy of the ball is 

When the spring is released all of the potential energy of the spring goes into the kinetic energy of the ball; therefore, 
 
solving for  we get:
 we get: 

And since momentum of the ball is  ,
,

Putting in numbers we get: 

