Aboy starts from point a and passes point c of a track abc shown in the figure. portion ab of length 1 is straight and portion bc is a semicircle of radius r (r< ). anywhere on the track, the modulus of the maximum acceleration of the hov is a find minimum transit time of the boy from a to c answer (-1) +2 2lr 2a

If the speed of a particle triples ,by what factor does its kinetic energy increase?

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.

Two point charges are on the y axis. a 3.90-µc charge is located at y = 1.25 cm, and a -2.4-µc charge is located at y = −1.80 cm. (a) find the total electric potential at the origin. v (b) find the total electric potential at the point whose coordinates are (1.50 cm, 0). v