Aladder that is 21 feet long is propped against a building. the bottom of the ladder was placed 4 feet from the base of the building. how high up on the building does the ladder reach? round the answer to the nearest tenth of a foot.
4.1 feet
17.0 feet
20.6 feet
21.4 feet

An electric motor is used to drive a power press which makes steel turning moment diagrams 323 pressings from a metal sheet. the motor runs at a mean speed of 50 rev/s. the torque required is 10.0nm for 0.2s, followed by 1.0nm for0.3 s with this sequence then being repeated. what is the minimum power required of the motor and the moment of incrtia required for the t1ywhcel if the speed fluctuations are to be restricted to 1.5%?