Jane and emily are going out in the sun. the protections they have used are listed below: jane: cap, uv blocking glasses, shirt with short sleeves emily: hat, sunglasses, spf 30 sunscreen who used better protection from the sun? (5 points) jane, because spf above 30 harms the skin emily, because a sunscreen protects the skin emily, because short sleeves lower skin temperature jane, because glasses reduce the amount of harmful rays

the dissolution of polymer can be thermodynamically described in 2 steps.

(newtons first law)

conservation of momentum law states :

momentum before collision = momentum after collision

momentum p (kg-m/s)= mass * velocity

say moving car=1 000 kg, velocity = 10 m/s then p = 1 000*10= 10 000 kg-m/s

say still car = 2 000 kg, velocity = 0 m/s then p = 2 000* 0 = 0 kg-m/s

total momentum prior to collision = 10 000 + 0 = 10 000 kg-m/s

momentum after collision = 10 000 kg-m/s

mass now = 1 000 kg+2 000 kg = 3 000 kg

10 000 = 3 000 kg* velocity m/s

10 000/3 000 = velocity

3.33 m/s = velocity after collision

an impulse is a force applied over time , momentum is exclusive of external forces and a perfect collision is implied