A2.99-m-long2.99-m-long rod, as measured in its rest frame, speeds by you longitudinally at 6.49×107 m/s6.49×107 m/s . you measure its length as it passes. by how many millimeters do you determine the rod has contracted?

The contraction in the rod is 71 mm.

Explanation:

Given that,

original length L'= 2.99 m

Speed

We need to calculate the length

Using expression for length contraction

Where,

Where, v = speed of observer

c = speed of the light

Put the value into the formula

The expression for the contraction in the rod

Hence, The contraction in the rod is 71 mm.

d

explanation:

v=uf/(u-f)

= 5.10/(5-10) convex lens has positive focal length

=50/-5

=-10 cm (formed at other side)

hi there!

out of the two, (b) precision would be more reasonable.   however, both a and b could be pretty reasonable.

-awesomerepublic   : )