What is the source of all waves?

If an electric circuit is not grounded it is best to reach out and touch it to provide the ground a.true or b.false

Which planet do you think would be easiest for humans to colonize some day?

Roger pushes a box on a 30° incline. if he applies a force of 60 newtons parallel to the incline and displaces the box 10 meters along the incline, how much work will he do on the box? a. 5.2 × 102 joules b. 6.0 × 102 joules c. -5.2 × 102 joules d. -6.0 × 102 joules