Which statements describe ways in which heat can be generated?

by rubbing two sticks together, enough heat can be generated to start a camp fire.
1) heat energy is generated by ice when it is melting.
2) heat can be created when tires roll on paved highway roads on a long road trip.
3) gravity generates heat by pulling solar energy toward earth's surface.
4) water creates heat energy when it condenses to form clouds.
5) burning broken tree limbs and other yard scraps creates heat energy.

Orange juice has a lower or higher viscosity than chocolate syrup

Waves that cause the most damage during an earthquake are a. surface waves c. s waves b. p waves d. ocean waves

In the future, people will only enjoy one sport: electrodisc. in this sport, you gain points when you cause metallic discs hovering on a field to exchange charge. you are an electrodisc player playing the popular four disc variant. the disks have charges of qa = −8.0 µc, qb = −2.0 µc, qc = +5.0 µc, and qd = +12.0 µc. (1) you bring two disks together and then separate them. you measure the resulting charge of these two disks and find that it is +5.0 µc per disk. which two disks did you bring together? (a) a and b (b) a and c (c)a and d (d)b and c(e) b and d (f) c and d. (2) you bring three disks together and then separate them. you measure the resulting charge of these three disks and find that it is +3.0 µc per disk. which three disks did you bring together? a, b, and c (a) a, b, and d (c) a, c, and d (d) b, c, and d. (3) given the resulting charge of each disk measured in (b) is +3.0 µc, how many electrons would you need to add to a disk of this charge to electrically neutralize it? electrons