Question

a particle moving in a straight line with initial velocity u and uniform acceleration a if the sum of the distances travelled In t^th and (t+1)^th second is 100 cm then it's velocity after t seconds in cm/s is
​

Answer 1

Explanation:

Correct option is

B

50

The distance travelled in n

th

second is

S

n

=u+

2

1

(2n−1)a ....(1)

So distance travelled in t

th

&(t+1)

th

second are

S

t

=u+

2

1

(2t−1)a ....(2)

S

t+1

=u+

2

1

(2t+1)a ....(3)

As per question,

S

t

+S

t+1

=100=2(u+at) ....(4)

Now from first equation of motion the velocity of particle after time t, if it moves with an acceleration a is

v=u+at ....(5)

where u is initial velocity

So from equation (4) and (5), we get v=50cm/s