Answer:
Gravitational force
Explanation:
Gravitational force is obviously one of the biggest obstacles in climbing. You are essentially going against this very strong force to pull your body mass up the beautiful terrain. Gravity is defined as the force of attraction between all masses in the universe, gravity is what allows the sport of climbing.
 
        
                    
             
        
        
        
By definition, the speed of an object is given by:

 Where,
 dr/dt: derived from the position with respect to time
 Therefore, speed has units of length over units of time.
 Thus, speed is a derived quantity, since it depends on the value of two other quantities.
 Answer:
 a derived quantity is:
 C. Speed
 
        
                    
             
        
        
        
Answer:
Explanation:
For calculating resistance of a conductor , the formula is 
R = ρ l / A , ρ is specific resistance , l is length and A is cross sectional area of wire. 
For first wire length is l₁ , area is A₁ resistance is R₁, for second resistance is R₂ , length is l₂ and area is A₂
Given , l₁ = 2l₂ , A₁ = 4A₂ , area is proportional to square of thickness. 
R₁ / R₂ = I₁A₂ / I₂A₁
= 2l₂ x A₁ / 4 I₂A₁
= 1 / 2 
2R₁ = R₂
Power = V² / R
Ratio of power = (V² / R₁) x (R₂ / V²)
= R₂ / R₁
= 2 . 
 
        
             
        
        
        
when wire is coiled upon a nail then it will posses magnetic characteristics
This is due to the coiled shape it will behave like a solenoid and the magnetic field of solenoid is given as

so here when wire is coiled up on a nail then due to the magnetic field of the coil the nail will attain magnetic characteristic.
so correct answer will be
<em>Possess magnetic properties </em>
 
        
                    
             
        
        
        
Chiefly in science fiction) an invisible barrier of exerted strength or impetus.