Hi! I am a practicum student in a 5th grade classroom. My mentor teacher gave me a worksheet to teach to the students tomorrow but no answer key. I just want to be sure I teach them the right things because I am quite confused. In which of the following scenarios is friction used and when is friction reduced?

a canoe glides down a river (I think reduced)
grease a bicycle chain (I think reduced)
butter a cake pan (I think reduced)
oil a door hinge (I think reduced)
lotion helps remove a tight gold ring (I think reduced)
a dolphin glides through the water (I think reduced)
press on a car’s brakes (I think used)
swan dive into a pool (I think used)
slide down a snowy hill (I think reduced)
walk across a wood floor in shoes (I think used)
rubbing two sticks together starts a fire (I think used)
grate cheese (I think used)
pedal your bicycle (I think used)
build a house of cards (I think used)
smooth wood with sandpaper (I think used)
walk across a wood floor in socks (I think reduced)
skate across the ice (I think used)
walk across the road (I think used)
slide down a grassy hill (I think used)
rub your hands together to warm them (I think used)

Thank you so much! Explanations would be nice, but you don’t have to.