Which of the following forces requires physical contact between objects?

the answer is: they occur when the sun, moon, and earth are aligned. in spite of their name, these tides occur twice a year in the spring and fall.

i think its y= -4x-14

weathering - colorado river carves land in arizona to form the grand canyon. cracks form in a sandstone wall surrounding a house. a marble statue near the science museum is changing color due to rainfall

erosion - after a rainstorm, soil and rock piees litter the roadways. the sand dunes in the sahara desert are changing shape.

here's your answer.