An ecologist studies a forest area for evidence of competition among organisms. she chooses a specific location where a tree was struck by lightning. the lightning strike caused the tree to fall over, leaving a space in the tree canopy for light to pass through. which of these observations provides the best evidence of competition?

many tree seedlings crowd the open space and attempt to grow in the sunlight.

snakes come into the open space and eat small rodents that can easily be spotted in the sunlight.

termites, with microorganisms in their stomachs to them digest wood, are found on the fallen tree.

a type of plant, called a bromeliad, grows in the branches of the fallen tree and continues to survive even though the tree has fallen

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)