Question

Please solve this question

Answer 1

From 4 to 5 he covers 2m
And from 5 to 6 he covered 2m in another direction
So d total = 2+2=4

Answer 2

A particle moves with 20m/s on x - axis with retardation of 4 m/s² .
e.g., initial velocity , u = 20m/s
retardation, a = -4 m/s²

we have to find velocity after 4 sec
use formula, v = u + at
v = 20 - 4 × 4 = 4 m/s

also we have to find where particle becomes rest.
final velocity , v = 0
0 = 20 -4t => t = 5sec
hence, after 5 sec, particle becomes rest.

so, total distance from 4 sec to 6sec = distance travelled from 4sec to 5 sec + distance travelled from 5 sec to 6 sec

= |4 × 1 - 1/2 × 4 × 1² | + |0 - 1/2 × 4 × 1² |

= |4 - 2| + | - 2|

= 2 + 2 = 4m

hence, option (3) is correct.