A spacecraft is travelling at a constant speed of 0.60c relative to the Moon - Scottish Highers Physics - Question 7 - 2015

Substituting the known values:

• $L = 190 \, m$ (length measured by the observer on the Moon)
• $v = 0.60c$

Now substituting these values into the length contraction formula: $L' = 190 \sqrt{1 - (0.60)^2}$

Calculating $(0.60)^2 = 0.36$ and then:

$L' = 190 \sqrt{1 - 0.36}$ $L' = 190 \sqrt{0.64}$ $L' = 190 \times 0.8$ $L' = 152 \, m$

Thus, the length of the spacecraft as measured by the astronaut on the spacecraft is 152 m, which corresponds to option B.