What are some machines or devices that depend on gravity to work?

Cars and planes are two examples because if there was no gravity they would float away.

Company has asked employees for suggestions on ways to personalize the retail customer's shopping experience. they want to supplement traditional appeals to the customer. you have come up with several ideas. select the idea or ideas you have decided to submit.c. designate two of the curtained areas in the women's dressing room for nursing mothers  d. tailor merchandise in each store to the preferences of customers in that geographical region