Speed v = distance travelled / time taken
 v = d / t
 v =  540 / 60h
v =   9 km /h
 
        
                    
             
        
        
        
8 miles per hour
because if it is moving at 4 miles every half hour that means you have to multiply it by two to get it in miles per hour and we all know that 4 times 2 is 8 so it would be 8 miles per hour =)
        
                    
             
        
        
        
The force needed to accelerate an elevator upward at a rate of  is 2000 N or 2 kN.
 is 2000 N or 2 kN.
<u>Explanation:
</u>
As per Newton's second law of motion, an object's acceleration is directly proportional to the external unbalanced force acting on it and inversely proportional to the mass of the object.
As the object given here is an elevator with mass 1000 kg and the acceleration is given as  , the force needed to accelerate it can be obtained by taking the product of mass and acceleration.
, the force needed to accelerate it can be obtained by taking the product of mass and acceleration.
                   
                   
So 2000 N or 2 kN amount of force is needed to accelerate the elevator upward at a rate of  .
.
 
        
             
        
        
        
Answer:
 
               
Explanation:
Given:
Charge = <em>q</em>
Electric field strength =
weight of the droplet = <em>mg</em>
The charge is suspended motionless. This is because the electric force on the charge is balanced by the weight of the droplet. 
electric force on charged droplet, 
This is balanced by the weight, 
Equating the two:

 
        
             
        
        
        
Answer:
The correct answer is "64 J".
Explanation:
The given values are:
Mass,
m = 52 kg
Velocity,
v = 6 m/s
Mechanical energy,
= 1000 J
Now,
The gravitational potential energy will be:
⇒ 
            
            
            
            