What speed is required for a length to contract to 80% of its proper length?
A) 0.80 c
B) 0.60 c
C) 0.40 c
D) 0.20 c
E) 0.50 c

Question

Quizplus · Accepted Answer

According to the Lorentz contraction formula, the length contraction (L') is given by L' = L(1-v^2/c^2)^0.5, where L is the proper length, v is the velocity of the object, and c is the speed of light. To find the velocity required for a length to contract to 80% of its proper length, we need to solve for v when L' = 0.8L. So, 0.8L = L(1-v^2/c^2)^0.5, which simplifies to (0.8)^2 = 1 - v^2/c^2. Solving for v, we get v = 0.6c. Therefore, the answer is B.

What Speed Is Required for a Length to Contract to 80