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When you drop a pebble from height a it reaches the ground with speed v if there is no air resistance. from what height should you drop it so it will reach the ground with three times the speed? (a) 9m (b) 3m (c) 6m (d) 18m

The necleus of an atom is made up of what subatomic particles?

Which of the following is not a transverse wave? a) soundb) lightc) radiod) all of thesee) none of these