Is iron and copper brittle​

In which of the following cases is work being done on an object? question 2 options: pushing against a locked door carrying a box down a corridor pulling a trailer up a hill suspending a heavy weight with a strong

1. how to locate the image in converging(concave) mirror and diverging (convex) mirror with salt. 2. how to locate the image in a converging (convex) lens and diverging (concave) lens with salt.

Aplane flying horizontally at an altitude of 1 mile and a speed of of 500mih passes directly over a radar station. find the rate at which the distance from the plane to the station is increasing when it is 2mi away from the station.