Explain why the formula F= -kx is negative in some cases?

What are the theoretical properties of a gas at a temperature of 0 kelvin?

Oxygen and nutrients are moved through the body by the: a. circulatory system c. lymphatic system b. digestive system d. reproductive system

There are two-speed cameras, one in an are where the speed limit is 30 km/h and another where the speed limit is 50 km/h. in which will there be a smaller time interval between the photographs? explain your answer.