An object is thrown upward with a speed of 14 m/s on the surface of planet X where the acceleration due to gravity is 3.5 m/s2. How long, in seconds, does it take for the object to reach the maximum height?

Question

anonymous · Answer

Multiple choice answers:
	A 1.4
	B 2.0
	C 8.0
	D 1.6
	E 4.0

festinger · Answer

The maximum height is reached when the object cannot travel higher anymore, and that is when it uses up all it's kinetic energy, and thus v=0

Using this fact and the formula v=u+at, taking upwards as positive
0=14-3.5*t
Solving t we get 4s.

anonymous · Answer

great thank you very much @Festinger !!!