J J Science Academy
Subject: Physics
Topic: 4. Linear kinematics
SubTopic: 4.5 Distance travelled in nth second
Test Type: N/A
1. An uniformly accelerated body travels a distance of 24 m in $(5^{\text {th }})$ second of its motion and 44 m in $(15^{\text {th }})$ sec of its motion. The acceleration of the particle will be
1) $(1 m / s^2)$
2) $(2 m / s^2)$
3) $(4 m / s^2)$
4) $(0.5 m / s^2)$
Hint: $(s_n = u + \frac{1}{2} g(2n-1))$ $(24 = u + \frac{9a}{2})$ (i) $(44 = u + \frac{29a}{2})$ (ii) (ii) - (i) gives $(20 = 10a)$ $(a = 2 m / s^2)$
2. A body, starting with some velocity, experiences uniform acceleration. It travels a distance of 20 m in $(5^{\text {th }})$ second and 36 m in $(9^{\text {th }})$ second. The acceleration of the particle (in $(m / s^2)$) is
Hint: $(s_n = u + \frac{1}{2} g(2n-1))$ $(20 = u + \frac{9a}{2})$ (i) $(36 = u + \frac{17a}{2})$ (ii) (ii) - (i) gives $(16 = 4a)$ $(a = 4 m/s^2)$
3. A particle starts moving along a straight line with velocity ' $(u)$ ' and a constant acceleration ' $(a)$ ', the initial velocity is
1) $(1 m / s)$
2) $(-1 m / s)$
3) $(2 m / s)$
4) $(-2 m / s)$
Hint: $(s_9 = u + \frac{1}{2}(4)[2(9)-1])$ $(36 = u + 34)$ $(u = 2 m / s)$
4. A particle starts moving along a straight line with velocity ' $(u)$ ' and a constant acceleration ' $(a)$ ', the distance it travels in $(15^{\text {th }})$ second is
1) 54 m
2) 58 m
3) 60 m
4) 64 m
Hint: $(s_n = u + \frac{1}{2} g(2n-1) = 2 + [\frac{1}{2} \times 4 \times 29] = 2 + 58 = 60 m)$