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QJEEM24Ph9b42: JEE Main 2024 Physics - Class 11 JEEM24Ph9b42 Solution: The displacement and the increase in the velocity of a moving…

The displacement and the increase in the velocity of a moving particle in the time interval of tt to (t+1)s(t+1) \mathrm{s} are 125 m125 \mathrm{~m} and 50 m/s50 \mathrm{~m} / \mathrm{s} , respectively. The distance travelled by the particle in (t+2)ths(\mathrm{t}+2)^{\mathrm{th}} \mathrm{s} is _________ m.

Step-by-Step Verified Solution

The displacement and the increase in the velocity of a moving particle from time tt to (t+1)s(t + 1) \mathrm{s} are 125 m125 \mathrm{~m} and 50 m/s50 \mathrm{~m} / \mathrm{s} , respectively. The distance traveled by the particle in (t+2)ths(\mathrm{t} + 2)^{\mathrm{th}} \mathrm{s} is calculated as follows:

Given that the acceleration is constant, we start with:

v=u+atv = u + at

When the velocity has increased by 50 m/s50 \mathrm{~m}/\mathrm{s} , the equation becomes:

u+50=u+a⇒a=50 m/s2u + 50 = u + a \quad \Rightarrow \quad a = 50 \mathrm{~m}/\mathrm{s}^2

Next, we consider the displacement:

125=ut+12at2125 = u t + \frac{1}{2} a t^2

Since this is given over a unit time interval (from tt to (t+1)(t + 1) ), we use:

125=u+a2125 = u + \frac{a}{2}

Substituting a=50 m/s2a = 50 \mathrm{~m}/\mathrm{s}^2 :

125=u+502⇒125=u+25⇒u=100 m/s125 = u + \frac{50}{2} \quad \Rightarrow \quad 125 = u + 25 \quad \Rightarrow \quad u = 100 \mathrm{~m}/\mathrm{s}

To find the distance traveled by the particle in (t+2)th(t + 2)^\text{th} second, we use:

Sn=u+a2[2n−1]S_n = u + \frac{a}{2} [2n - 1]

For n=t+2n = t + 2 (i.e., the (t+2)th second):

S(t+2)=u+a2[2(t+2)−1]S_{(t+2)} = u + \frac{a}{2} [2(t+2) - 1]

With u=100u = 100 and a=50a = 50 :

S(t+2)=100+502[2(t+2)−1]=100+25×[2(t+2)−1]=100+25×(2t+4−1)=100+25×(2t+3)=100+25×5=100+125=225 mS_{(t+2)} = 100 + \frac{50}{2} [2(t+2) - 1] = 100 + 25 \times [2(t+2) - 1] = 100 + 25 \times (2t + 4 - 1) = 100 + 25 \times (2t + 3) = 100 + 25 \times 5 = 100 + 125 = 225 \mathrm{~m}

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