You are pushing on a heavy door, trying to slide it open. if your friend stands behind you and you push, how have the forces changed?
a. the net force applied will increase.
b. the net force will decrease.
c. there will be less friction.
d. the applied force does not change

Ameadow ecosystem includes many species of grasses and small shrubs, several herbivores, and a few carnivores. a fungus colonizes the meadow and kills most of its vegetation. what is most likely to happen to the populations of herbivores and carnivores in the ecosystem? a. the populations of herbivores and carnivores will increase because there will be less competition for chemical energy. b. the populations of herbivores and carnivores will remain stable because the fungus cannot infect these organisms. c. the populations of herbivores will decrease because of vegetation loss, but the population of carnivores will remain stable. d. the populations of herbivores and carnivores will decline because less chemical energy will be stored in the ecosystem.

Depending on the organism the number of in a cell may change

World class speed skaters can skate a 3,000-m course in about 4 minutes. what is their average speed for this course. a. 12.5m/s b. 1.33m/s c. 13.3m/s d. 1.25m/s