Question

an object is thrown straight up, it stays in the air for 13 seconds. a)what is the acceleration at the highest point? b)Are the velocities of 7 seconds and 17 seconds the same?​

Answer 1

Answer:

Explanation:Assumption: g=9.8 m/s2 holds true (maximum height reached is small compared to the radius of earth)

Velocity of the ball at maximum height is zero, v=0

v2−u2=2aH                          

0−(49)2=2×(−9.8)×H          

⟹H=122.5 m                

v=u+at

0=49−9.8t            

⟹t=5 s

∴ Total time taken by ball to return to the surface, T=2t=10 s