List three ways the earth is different today from when it was first formed

What do elements in a family tend to share. a.) similar periods b.) similar groups c.) similar atomic symbols d.) similar chemical properties and characteristics

Abike rider starts from rest and accelerates 28.0 meters down a slope in 5.00 seconds. what is her acceleration? select one: a. 3.21 m/sec2 b. 1.75 m/sec2 c. 9.80 m/sec2 d. 2.24 m/sec2

Apulley system is used to lift a 2,000 newton engine up a distance of 3 meters. the operator must apply a force of 250 newtons to the chain of the pulley system to lift the motor. to lift the engine 3 meters, the operator must pull a total of 30 meters of chain through the pulley system. what is the value of di?