Which statement best describes the importance of joints in the roadways of Bridges ? a. Joints strengthen the roadway to support cars and trucks

b. Joints allow the roadway to expand and contract with varying outside temperatures

c. Joints allow the roadway to expand and contract as cars put force on the bridge

d. Joints allow the bridge to be built in smaller, easier to assemble pieces.

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.

Madison pushes with a 210-n horizontal force on a 24-kg crate of coffee resting on a warehouse floor. the force of friction on the crate is 74 n. what is the acceleration?

4. if you were an astronaut on the moon, what would you experience? what would you see from your perspective?