12. A person in a wheelchair did 70.8 J of work on the chair to get it moving from rest at the bottom of a ramp, taking 1.00 s to do so. She turned the wheel (which has a radius of 40.0 cm) one quarter turn before letting go and rolling back down. If the combined mass of her and the chair was 98.0 kg, what was her final velocity when she passed back over the bottom of the ramp?

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WILL GIVE

How do we measure or think of speed in the united states?

The friction of the water on a boat produces an acceleration of -10. m/s2. if the boat is traveling at 30. m/s and the motor is shut off, how long it take the boat to slow down to 5.0 m/s?

22. the top of a cliff is located a distance h above the ground. at a distance h/2 there is a branch that juts out from the side of the cliff, and on this branch a bird's nest is located. two children throw stones at the nest with the same initial speed, one stone straight downward from the top of the cliff and the other stone straight upward from the ground. in the absence of air resistance, which stone hits the nest in the least amount of time?