As shown, this is a high-speed camera.

The actual length of the bullet is 2.0 cm. ..

According to the ratio of neutron bomb to Parker brand in the photo, the width of Parker brand is about 8cm.

So the time for the bullet to pass through Parker is t = XV = 0.02+0.08900 =1.1×10-4s.

So the answer is: 1. 1× 10-4.