the air in the room has a mass of 50 kg and a specific heat of 1000j. What is the change in thermal energy of the air when it warms from 20 degrees celsius to 30 degrees celsius?

The clock that rings the bell known as big ben has an hour hand that is 9.0 feet long and a minute hand that is 14 feet long, where the distance is measured from the center of the clock to the tip of each hand. part a what is the tip-to-tip distance between these two hands when the clock reads 12 minutes after four o'clock? express your answer using two significant figures.