31. Which materials would most likely be used by designers of ornithopters to mimic the bone structures of pterosaur wings? A. heavy metals to prevent bends and tears in the wings B. wooden replicas of bones to create identical structures for the devices C. lightweight metals and open-space structures for the wings D. plastic replicas of bones that have a completely filled-in structure

iron would move it is magnetic there is a mag field around the current in the wire

a lot of it means it can be "burned" for energy and sold at one price. if it is scarce, the price will go up

when jerome paddle in flowing river towards east the net speed of jerome will increase

so the net speed of jerome will be given as

now the speed of paul will be same as it is given as he is running on the ground

so

so here we can say since the speed of jerome is more so he will win the race

now as we know the distance so the time difference is given as

so jerome will reach first and the time difference will be 203.55 s or 3.4 min