Adistance-time graph indicates that an object 100 m in 4s and then remains at rest for 6s what is the average speed of the object

The percent efficiency of a machine can never be 100% (or greater), because in the real world some energy is always converted into a. heat b. work c. input force d. output force

The star betelgeuse is about 600 light-years away. if it explodes tonight, a. we'll know because debris from the explosion will rain down on us from space. b. we'll know it immediately because it will be brighter than the full moon in the sky. c. we won't know about it until 600 years from now. d. none of the above.

Sound travels slower in colder air that it does in warmer air. make a claim about the effect of air temperature on the speed of sound. support your claim with evidence