I think its d. but im not sure
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 .
Answer:
Almost all machines require energy to offset the effects of gravity, friction, and air/wind resistance. Thus, no machine can continually operate at 100 percent efficiency.
Answer:the force is needed to stretch it farther.
Explanation: the definition of force is push or pull so imagine stretching a rubber band your pulling the band which means you increase the force.