Emily sprains her ankle on her way home from school. her mom suggests she use an “instant cold pack” to reduce the swelling. when emily’s mom hands her the cold pack, it is room temperature. the instructions on the pack tell emily to pop a button inside the ice pack to open a packet of chemicals. once emily has popped the button, she notices that the cold pack immediately gets cold. she places it on her swollen ankle. write a thoughtful and complete response (3+ sentences) that describes what happened to the energy as it is first in the cold pack (before emily pops the button), then when she pushes the button, and then after emily has placed the cold pack on her ankle. discuss transfers and transformations of the energy.

Explain to someone who knows nothing about fossils the study of invertebrate paleontology and how it scientists understand the history of the earth. be sure your explanation contains a minimum of two complete sentences.

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)

Question part points submissions used suppose that 2 j of work is needed to stretch a spring from its natural length of 26 cm to a length of 36 cm. (a) how much work is needed to stretch the spring from 28 cm to 32 cm? (round your answer to two decimal places.)