Aboy drags a 100 n sled up a 20 slope at constant velocity. if the coefficient of friction between sled and hill is 0.20, what force must he exert at an angle of 35 with respect to the hill?

Describe how the fermi level changes with donor level, temperature and contact with p and n type semiconductors

The material that keeps its new shape after it is stretched is called?

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.