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How many significant digits does the number 15.00 have?

Consider the following five graphs (note the axes carefully). Which of these represents motion at constant speed?

A stone is thrown horizontally with an initial speed of 10 m/s from the edge of a cliff.  A stop watch measures the stone’s trajectory time from the top of the cliff to the bottom to be 4.3 s.  What is the height of the cliff?

A jumper in the long-jump goes into the jump with a speed of 12 m/s at an angle of 20° above the horizontal.  How long is the jumper in the air before returning to the Earth?

At what angle should a water-gun be aimed in order for the water to land with the greatest horizontal range?

A car maintains a constant velocity of 100 km/hr for 10 seconds. During this interval it acceleration is:

A polar bear starts at the North Pole.  It travels 1.0 km south, then 1.0 km east, then 1.0 km north, then 1.0 km west to return to its starting point.  This trip takes 45 min.  What was the bear’s average velocity?

A girl throws a rock horizontally, with a velocity of 10 m/s, from a bridge.  It falls 20 m to the water below.  How far does the rock travel horizontally before striking the water?

A stone is released from rest from the edge of a building roof 190 m above the ground. Neglecting air resistance, the speed of the stone, just before striking the ground, is:

If   Vx = 6.80 units and   Vy = 7.40 units determine the magnitude and direction of V.