It is round or say spherical to widen the range of photography and it is designed to focus the image as the ray are coming from infinity so !!
I am not an expert of camera but ya it is the main theme !!
In 6 secs, the dog covers-
S=vt
8.9*6 = 53.4 m.
In the same time, the cat covers, 53.4-3.8 = 49.6 m.
Thus, speed of the cat, v= s/t,
= 49.6/6 = 8.267 m/s
Beta decay is very complex phenomena in natural radioactive decay. There are 3 types of Beta decay.
B+ decay (Beta plus or Beta positive or positron decay):
is the conversion of a proton into a neutron plus a positron and an electron neutrino.
B- decay (Beta negative or Beta nought):
is the conversion of a neutron into a proton plus an electron and a electron antineutrino.
Note: a positron is the a positive electron or the antiparticle of the electron.
Hope it helps
Heat equation, Q = m.c.Δt
Here, c represents " the specific heat of the substance "
Hope this helps!