Which force keeps and object moving in a circle?

Two students, each riding bicycles, start from the same apartment building and ride to the same building on campus, but each takes a different route. the first student rides 1100 m due east and then turns due north and travels another 1430 m before arriving at the destination. the second student heads due north for 1930 m and then turns and heads directly toward the destination.at the turning point, how far is the second student from the destination?

Which of the following is not a physical property of mattera. melting pointb.heat of combustionc. viscosityd. boiling point

How does the formation of intrusive and extrusive igneous rocks differ?