Two chains of length 1.0m are used to support a lamp the distance between the two chains along the ceiling is 1.0m. what is the vertical distance from the lamp to the ceiling?

Answer 1

The chain length is L = 1 meter.
The chains hang at an angle
sin^-1(0.5) = 30 degrees from vertical.
The distance of the lamp from the ceiling is L*cos30 = 0.866 meters

This is not about physics

Answer 2

how to solve the driver of a pickup truck going 100km/h applies the brakes, giving the truck a uniform deceleration of 6.50m/s2 while it travels 20.0m. a) what is the speed of the truck in kilometers per hour at the end of the distance? b)how much time has elapsed?