If it is eight meters per second, and the total distance he has to travel is four hundred meters to complete the race, you divide the total length needed to travel by the average speed per second to see the amount of seconds required to complete the race at that speed.
8 meters per second: Speed of runner
400 meters: Total distance
400/8=50
50 seconds to complete the race at the eight of 8m/s.
Answer:
No, it is not necessary for them to have same mass.
Explanation:
Let both bodies have a density d1 and d2 respectively.
Since their volumes are equal V1 = V2
we know that, https://tex.z-dn.net/?f=%5Cfrac%7Bmass%7D%7Bvolume%7D
Hence, d1 = and d2 =
Taking the ratio of densities,we get
This implies that unless the bodies have same densities, the mass of the two bodies will not be same.
For example a Helium-4 nucleus has two protons and two neutrons. The mass of the Helium-4 nucleus is less that the masses of two free protons and two free neutrons.
Right before it breaks of, because all the other options are examples of Kinetic energy while the A. answer is the only one describing potential energy.