I need help on this. someone help please!

a. The phone will be at 92% and the tablet will be at 88%

b. One hour and 15 minutes for both devices to finish charging.

Step-by-step explanation:

For Part A), we can find that Sam's phone battery is increasing by 12% every 10 minutes. By multiplying 12 by 3 (30 minutes) and adding it to the 56% from the first 30 minutes, we get the answer 92%. The tablet charges 12% per every 15 minutes, and one hour has four sets of 15 minutes. So 12 times 4 and then added to 40% gives us 88%.

For Part B), we must calculate how much time it takes before both devices are fully charged. Because it charges at a slower rate and will finish last, we must rely on the rate of the tablet for this question. At a rate of 12% per 15 minutes, Sam's devices would both be fully charged after an hour and 15 minutes. This is because an additional 15 minutes would give the tablet 12% more battery, and 88 + 12 = 100. If you also needed to know when the phone would finish charging by itself, you would find that the phone only needed 8% left to become 100%. The phone charges at 12% per 10 minutes, and 8 is 2/3 of 12. This would mean the phone would need roughly an additional 7 minutes to charge, making for a total of one hour and 7 minutes for the phone.

Hope this helps!

constant acceleration- a

constant velocity- c

no velocity or acceleration- b

explanation:

for body moving with a constant acceleration, the rate of change of displacement changes over time. this is proven by the increasing gradient of the curve (a) against time.

a body that is moving at constant velocity covers equal distances over equal periods of time, thus the straight line with a constant gradient c.

a stationary body   covers no displacement as time elapses. thus the flat line with   zero gradient.