A ball of mass 10 g is moving with a velocity of 50 m −1 . On applying a constant force on ball for 2.0 s, it acquires a velocity of 70 m −1 . Calculate : (i) the initial momentum of ball, (ii) the final momentum of ball, (iii) the rate of change of momentum, (iv) the acceleration of ball, and

Work = force × a. work b. energy c. distance d. momentum

Agroup of students is studying convection currents. they fill two identical balloons with the same amount of helium. one balloon is placed in a freezer and the other in an area with warm air. after 10 minutes, the balloons are released from a height of 1 meter. which of the following do the students most likely observe? question 2 options: the balloons rise at the same rate. both balloons are the same size. the ballons both rise. the cold ballon is larger than the warm balloon. the cold balloon expands and rises. the warm balloon shrinks and sinks. the warm balloon expands and rises. the cold balloon shrinks and sinks.

Write down two additional questions about earth's magnetic field that will make your presentation more informative.