Answer:
statements <em><u>2, 3, 4, and 7</u></em> are true
Explanation:
Mechanical energy (ME) is the sum of potential energy (PE) and kinetic energy (KE). When the toy falls, energy is converted from PE to KE, but by conservation of energy, ME (and therefore PE+KE) will remain the same.
Therefore, ME at 0.500 m is the same as ME at 0.830 m (the starting point). It's easier to calculate ME at the starting point because its just PE we need to worry about (but if we wanted to we could calculate the instantaneous PE and KE at 0.500 m too and add them to get the same answer).
At the start:
ME = PE = mgh
ME = 0.900 (9.8) (0.830)
ME = 7.32 J
Answer:
He will complete the race in total time of T = 10 s
Explanation:
Total distance moved by the sprinter in 2.14 s is given as



now the distance remaining to move

now he will move with uniform maximum speed for the remaining distance
so we will have


so the total time to complete the race is given as

Objects can have the same mass (but different <span>compositions). Only mass or volume cannot tell you if the object is solid or vo</span>lumes) or same volume (but different masses)