J J Science Academy

Question 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: $$s_n = u + \frac{1}{2} g(2n-1)$$ $$24 = u + \frac{9 a}{2}$$ $$44 = u + \frac{29 a}{2}$$ (ii) - (i) gives $$20 = 10a$$ $$a = 2 m/s^2$$

Question 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

1) 4 2) 2 3) 6 4) 8

Hint: $$s_n = u + \frac{1}{2} g(2n-1)$$ $$20 = u + \frac{9 a}{2}$$ $$36 = u + 17a$$ (ii) - (i) gives $$16 = 4a$$ $$a = 4 m/s2$$

Question 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: $$s_9 = u + \frac{1}{2}(4)[2(9)-1]$$ $$36 = u + 34$$ $$u = 2 m/s$$

Question 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: $$s_n = u + \frac{1}{2} g(2n-1) = 2 + [\frac{1}{2} \times 4 \times 29] = 2 + 58 = 60 m$$