Answer:
1. 2.5s
Explanation:
1. For time, divide Distance / speed
25m / 10
=2.5s
 
        
             
        
        
        
Here the block has two work done on it
1. Work done by gravity
2. Work done by friction force
So here it start from height "h" and then again raise to height hA after compressing the spring
So work done by the gravity is given as

Now work done by the friction force is to be calculated by finding total path length because friction force is a non conservative force and its work depends on total path


Total work done on it

So answer will be 
None of these
 
        
                    
             
        
        
        
The law of Ohm defines the relationship in an electrical circuit between voltage, current and resistance: I = v / r. The current is directly proportional to the voltage and the resistance is inversely proportional.
 
        
                    
             
        
        
        
Answer:
Acceleration = 0.9144 m/s^2
Explanation:
Initial speed = 45 ft/s
Final speed = 60 ft/s
Time = 5 sec
Acceleration = a = (v-u) / t
                      = 60-45 / 5
                      = 0.9144 m/s^2