D. With the same number of protons and different number of neutrons.
Whenever the motion of an object changes . . . speeding up, or slowing down,
or changing direction . . . that change is called "acceleration". Acceleration is produced by force on the object.If there is no force on the object, then there is no acceleration. That means that
its motion doesn't change. The object remains in constant, uniform motion .
moving with steady speed, in a straight line.
No force is necessary to keep an object moving, only to change its motion.
Answer:
we can do it again and again and again and again and again and again
Answer:
The final temperature of the system is 27.3°C.
Explanation:
Heat lost by aluminum = 3.99 × 0.91 × (100-T)
= 3.631 (100-T)
Heat gained by water = 10 × 4.184 × (T-21)
= 41.84 (T-21)
As,
Heat gained = Heat loss
or, 3.631(100-T) = 41.84(T-21)
or,363.1 - 3.631 T = 41.84 T - 878.64)
or, (41.84+ 3.631) T = 878.64 +363.1
or T= 
or, T = 27.3°C
Hence the final temperature is 27.3°C.