Define the law of conservation of momentum in one sentence

Most energy in an ecosystem comes originally from_

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?

Mark saxby is set to kick the field goal to win the state championship for olathe east. he is 47m away from the goalposts, and he kicks the ball at a speed of 25.0m/s at an angle of 30.0°. if the cross bar on the goalposts is 3.00m above the ground, will the ball make it over the cross bar? and if it does make it, by how much will it clear?