Sam and his dad went grocery shopping. as they went up and down the aisle, adding items to their cart, something changed. the cart got heavier as they added groceries. as the cart became heavier, it also became harder to push. what else most likely changed as sam and his dad shopped? a) the force of the cart. b) the speed of the cart. c) the size of the cart. d) the direction of the cart.

Ineed asap! list 3 examples in which friction us or makes things easier in our daily life. explain the effect of friction for each. *make sure you explain the effect of friction for each example! *

Air is contained in a variable-load piston-cylinder device equipped with a paddle wheel. initially, air is at 400 kpa and 17°c. the paddle wheel is now turned by an external electric motor until 75 kj/kg of work has been transferred to air. during this process, heat is transferred to maintain a constant air temperature while allowing the gas volume to triple. calculate the required amount of heat transfer in kj/kg.

What happens to an isotope during radioactive decay?