An object of 4cm high is placed on and perpendicular to the axis of a concave mirror of a radius of curvature 2cm and it's 8cm from the mirror, find the position, nature and magnification of the image formed

Awave is produced in a rope. the wave has a speed of 33 m/s and a frequency of 22 hz.

Most short-period comets do not have randomly oriented orbits because

The number of passengers who arrive at the platform of a subway station for the 10 am train is a random variable with a mean of 120 and a variance of 16. find the lower bound of the probability that there will be between 100 and 140 passengers (round off to second decimal place).