## modphysnoob Group Title A mechanism on Earth used to shoot down geosynchronous satellites that house laser-based weapons is finally perfected and propels golf balls at 0.94c. a) How far will a detector riding with the golf ball initially measure the distance to the satellite? [Geosynchronous satellites are placed 3.58x104 km above the surface of the Earth.] b) How much time will it take the golf ball to make the journey to the satellite in the Earth’s frame? How much time will it take in the golf ball’s frame? one year ago one year ago

1. modphysnoob Group Title

@Jemurray3 do I use length contraction on this? if so , how?

2. Jemurray3 Group Title

Yes, for the first part. As straightforwardly as you possibly could... $L = L_0 \sqrt{1-v^2/c^2}$

3. modphysnoob Group Title

so L0 would be 3.58x10^4 ?

4. Jemurray3 Group Title

Yes, the proper distance is measured in the earth frame because the geosynchronous satellites are at rest relative to the earth.

5. modphysnoob Group Title

for b) do I do just normal calcuation using t= l/v then lorentz transform that t?

6. modphysnoob Group Title

@Jemurray3

7. Jemurray3 Group Title

Yes. Alternatively, you could divide the contracted distance by the velocity.

8. modphysnoob Group Title

oh I see, that works too Thank you for your help