Feel the back of your skull. Go ahead, feel it! You may feel a small bump, below which is an opening where the spinal cord enters your skull. The relocation of this opening toward the bottom of the skull is significant in evolutionary biology. Why

Acceleration is a direct result of a.) balanced forces b.) unbalanced forces c.) gravity d.) velocity

Why do we perceive objects as retaining their brightness under different lighting levels?

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 8 options: the cold balloon expands and rises. the warm balloon shrinks and sinks. 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 warm balloon expands and rises. the cold balloon shrinks and sinks.