What happens when a particle of matter meets its corresponding antiparticle of antimatter?
a) they can form a complete atom. b) the combined mass of the two particles is completely transformed into energy (photons). c) they fuse to make a heavier particle. d) the question makes no sense, since antimatter does not really exist.

The correct answer is B) the combined mass of two particles is completely transformed into energy (photons).

the minimum constant speed at which she can catch the train is 2.7 m/s

given:

acceleration = 0.6

time = 4.5 s

to find:

velocity = ?

formula used:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

solution:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

v = 0 + (0.6 × 4.5)

v = 2.7 m/s

the minimum constant speed at which she can catch the train is 2.7 m/s