A player kicks a

Question:

A player kicks a football with an initial speed of $25 \mathrm{~ms}^{-1}$ at an angle of $45^{\circ}$ from the ground. What are the maximum height and the time taken by the football to reach at the highest point during motion ? (Take $\mathrm{g}=10 \mathrm{~ms}^{-2}$ )

  1. $\mathrm{h}_{\max }=10 \mathrm{~m} \quad \mathrm{~T}=2.5 \mathrm{~s}$

  2. $\mathrm{h}_{\max }=15.625 \mathrm{~m} \quad \mathrm{~T}=3.54 \mathrm{~s}$

  3. $\mathrm{h}_{\max }=15.625 \mathrm{~m} \quad \mathrm{~T}=1.77 \mathrm{~s}$

  4. $\mathrm{h}_{\max }=3.54 \mathrm{~m} \quad \mathrm{~T}=0.125 \mathrm{~s}$


Correct Option: , 3

Solution:

$\mathrm{H}=\frac{\mathrm{U}^{2} \sin ^{2} \theta}{2 \mathrm{~g}}$

$=\frac{(25)^{2} \cdot(\sin 45)^{2}}{2 \times 10}$

$=15.625 \mathrm{~m}$

$\mathrm{T}=\frac{\mathrm{U} \sin \theta}{\mathrm{g}}$

$=\frac{25 \times \sin 45^{\circ}}{10}$

$=2.5 \times 0.7$

$=1.77 \mathrm{~s}$

Leave a comment

Close

Click here to get exam-ready with eSaral

For making your preparation journey smoother of JEE, NEET and Class 8 to 10, grab our app now.

Download Now