Agroup of students were collecting soil samples near a river. one student noted there was a lot of sand in one of the samples. he said" all this sand must have washed up from beach where the river enters the ocean." another student said, "i think it came from the rocks in the mountains. but there aren't any mountains near us. i don't understand how the sand got there." what would you tell the students to them solve where the sand came from?

In which of the following cases is work being done on an object? question 2 options: pushing against a locked door carrying a box down a corridor pulling a trailer up a hill suspending a heavy weight with a strong

The ultracentrifuge is an important tool for separating and analyzing proteins. because of the enormous centripetal accelerations, the centrifuge must be carefully balanced, with each sample matched by a sample of identical mass on the opposite side. any difference in the masses of opposing samples creates a net force on the shaft of the rotor, potentially leading to a catastrophic failure of the apparatus. suppose a scientist makes a slight error in sample preparation and one sample has a mass 10 mg larger than the opposing sample. if the samples are 12 cm from the axis of the rotor and the ultracentrifuge spins at 70,000 rpm, what is the magnitude of the net force on the rotor due to the unbalanced samples? ( be thorough on your answer)

Each neuron shown in this figure innervates a group of muscle fibers. what is the term for a group of muscle fibers innervated by a single neuron?