Question

the displacement x of a particle in time t is given by 10t^2-4t-x =0. where x is in meter and t in second. the distance covered by the body in 4th second of motion

Answer 1

it is given that
t = 4sec
so putting the value

10(4)^2-4(4)-x =0

10×16-16-x=0

160 -16-x = 0

144-x =0

x= 144m

Answer 2

Answer:

We know that the for 4th second there we use formulae of s4th - s3rd and that is

We put the value of t =4 in given equation and t=3in given equation and subtract the value of S3 from S4

Then

10*4*4-4*4-x=0

X=144 it is the value of S4

Now, 10*3*3-3*3-x=0

X=78

So, the final answer is 144-78=66