Answer:
Part a)

Part b)

Part c)

Part d)
Net force on a closed loop in uniform magnetic field is always ZERO

Explanation:
As we know that force on a current carrying wire is given as

now we have
Part a)
current in side 166 cm and magnetic field is parallel 
so we have

here we know that L and B is parallel to each other so 

Part b)
For 68.1 cm length wire we have

here we know that


so we have


Part c)
For 151 cm length wire we have

here we know that


so we have


Part d)
Net force on a closed loop in uniform magnetic field is always ZERO

 
        
             
        
        
        
Answer:
Buoyant force = 3.0 N
The object will not float.
Explanation:
Apparent weight of a body immersed in water is the actual weight of object minus buoyant force
Given in the question that;
Weight of object in air = 7.0 N
Apparent weight of object = 4.0 N
4.0 N = 7.0 N - Buoyant force
Buoyant force = 7.0 - 4.0 = 3.0 N
In this case, the buoyant force is less than weight of the object thus the object will sink.
 
        
             
        
        
        
Reduce friction because friction just makes things harder
        
                    
             
        
        
        
Answer:
In physics, work is the amount of energy required to perform a given task (such as moving an object from one point to another). We start by defining the scalar product of two vectors, which is an integral part of the definition of work, and then turn to defining and using the concept of work to solve problems.