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QJEEM21Pha952: JEE Main 2021 Physics - Class 11 JEEM21Pha952 Solution: Two spherical balls having equal masses with radius of 5 cm…

Two spherical balls having equal masses with radius of 5 cm each are thrown upwards along the same vertical direction at an interval of 3s with the same initial velocity of 35 m/s, then these balls collide at a height of ............... m. (Take g = 10 m/s2)

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JEE Main 2021 (Online) 26th August Morning Shift Physics - Motion in a Straight Line Question 59 English Explanation

When both balls will collide

y1 = y2

35t−12×10×t2=35(t−3)−12×10×(t−3)235t - {1 \over 2} \times 10 \times {t^2} = 35(t - 3) - {1 \over 2} \times 10 \times {(t - 3)^2}

35t−12×10×t2=35t−105−12×10×t2−12×10×32+12×10×6t35t - {1 \over 2} \times 10 \times {t^2} = 35t - 105 - {1 \over 2} \times 10 \times {t^2} - {1 \over 2} \times 10 \times {3^2} + {1 \over 2} \times 10 \times 6t

0 = 150 −- 30 t

t = 5 sec

∴\therefore Height at which both balls will collied

h=35t−12×10×t2h = 35t - {1 \over 2} \times 10 \times {t^2}

=35×5−12×10×52= 35 \times 5 - {1 \over 2} \times 10 \times {5^2}

h = 50 m

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