J J Science Academy
Question 1:
An uniformly accelerated body travels a distance of 24 m in $( 5^{th} )$ second of its motion and 44 m in $( 15^{th} )$ 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} a(2n-1) )$$ ( 24 = u + \frac{9 a}{2} )$ (i)$ ( 44 = u + \frac{29 a}{2} )$ (ii)(ii) - (i) gives$ ( 20 = 10a )$ $( a = 2 m / s^{2} )$
Question 2:
A body, starting with some velocity, experiences uniform acceleration. It travels a distance of 20 m in $( 5^{th} )$ second and 36 m in $( 9^{th} )$ second. The acceleration of the particle (in $( m / s^{2} )$ ) is
Hint:
$( s_n = u + \frac{1}{2} a(2n-1) )$$ ( 20 = u + \frac{9 a}{2} )$ (i)36 = u + 17a(ii) - (i) gives16=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 $( 15^{th} )$ second is
1) 54 m
2) 58 m
3) 60 m
4) 64 m
Hint:
$( s_n = u + \frac{1}{2} a(2n-1) = 2 + [\frac{1}{2} \times 4 \times 29] = 2 + 58 = 60 m )$