The time taken by the stone to hit the ground would be 5.12 seconds.
<h3>What are the three equations of motion?</h3>
There are three equations of motion given by Newton
The first equation is given as follows
v = u + at
the second equation is given as follows
S = ut + 1/2×a×t²
the third equation is given as follows
v² - u² = 2×a×s
Keep in mind that these calculations only apply to uniform acceleration.
As given in the problem, a stone is dropped from the helicopter which is ascending at the speed of 19.6 m/s
height(S) = 156.8 meters
initial velocity(u) = -19.6 m/s
acceleration(a) = 9.81 m/s²
By using the second equation of motion given by newton
S = ut + 1/2at²
S = 156.8m ,u= -19.6 m/s , a= 9.81 m/s² and t =? seconds
156.8= -19.6t + 9.81t²
t = 5.12 seconds
Thus, the time taken by the stone to hit the ground would be 5.12 seconds.
Learn more about equations of motion from here,
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the answer to you question is D.
Answer:
gravity is changed by a factor of 10/16
Explanation:
gravitational force = m1 m2 G / r^2 now change the m1 and r
= 10 m1 m2 G/ (4 r)^2
= 10 /16 m1 m2 G / r^2
10 /16 the earth's gravity
