A rubber stopper attached to a string is travelling in a circular path above a students' head. If the radius of the circle that the stopper is travelling is 0.5m and it takes 2.0 s for the stopper to make one complete revolution, what is the velocity of the rubber stopper?

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

How many molecules are present in 3 mols of silicon dioxide (sio2)?

Astone is dropped with no initial velocity from the top of a cliff and hits the ground a time of 3.9 s later. what is the height of the cliff, in units of meters? you may assume that air resistance is negligible. give the answer as a positive number question 15 a figure skater is rotating at a rate of 200 revolutions per minute. what is the angular speed, in units of rad/s? 200 o 20.9 12000 o 3.33