A) First
B) Second
C) Third
D) Fourth
Correct Answer: D
Solution :
Given, \[x=0.20\text{ }m,y=0.20\text{ }m,\,u=1.8m/s,\] Let the ball strike the nth step of stairs. Vertical distance travelled \[=ny=n\times 0.20=\frac{1}{2}g{{t}^{2}}\] Horizontal distance travelled \[=nx=ut\] or \[t=\frac{nx}{u}\] \[\therefore \] \[ny=\frac{1}{2}g\times \frac{{{n}^{2}}{{x}^{2}}}{{{u}^{2}}}\] Or \[n=\frac{2{{u}^{2}}}{g}.\frac{y}{{{x}^{2}}}\] \[=\frac{2\times {{(1.8)}^{2}}\times 0.20}{9.8\times {{(0.20)}^{2}}}\] \[=3.3\approx 4\]You need to login to perform this action.
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