Can pair annhilation takes place in vacuum or free space?

A particle is projected in vertical plane such that after 5 seconds its velocity becomes horizontal. The maximum height attained by the projectile from point of projection is n3 m. The value of n is _______. (g = 10 m/s2)

Two particles approach each other from very large distance as shown, . if the least separation between the particles is b, what is the speed of M in center of mass frame when particles are closest? (gravity negligible)

Can the sum of two equal vectors be equal to either vector

A nucleus X184 at rest emitt alpha particle With kinetic energy 9.0MeV. The product Nucleus is Y. The values of Binding energy per nucleon of alpha particle & Y differ by 1.5MeV. The values of Binding energy per nucleon of X & Y differ by (n÷230) MeV, then n is

SUBJECT: PROBLEM BASED ON LINE DETECTION.Query: How to apply all the filters for line detection on the following piece of image (provided below)? Explain its Observations to comment on its results.