a stone is thrown vertically upward with a velocity of 30m/s. how high will it rise? After how much time will it return to the ground (G= 10m/ s)
Answers
Explanation:
5 t² - 20 t = 0; ==> 5 t (t - 4) = 0; ==> t= 0 sec. or t = 4 sec. The body would be at the ground at the beginning ie at t =0 and again at t = 4 s. A ball is thrown vertically up with a speed of 14 m/s. Two seconds later, a second ball is dropped from the same point.❤❤
The stone will rise to a height of 45m and it will return to the ground after 6 seconds
- Initial velocity, u = 30 m/s
- Using 3rd equation of motion
v²-u² = 2× (-g) × h
(g is taken negative because it is acting against the direction of stone)
⇒0 - (30)² = 2 × (-10) × h
h = 900/20
h = 45 m
- Using 1st equation of motion
v = u + (-g)t
0 = 30 - 10t
t = 30/10 = 3 sec
- This is the time required to reach the maximum height.
- Total time top return to the ground = 2 × 3 = 6 sec.