Question

a man runs for first 120m at 6m/s and next 120m at 3m/s in the same direction
a)average velocity?
b)total time?​

Answer 1

Answer:

a. Average speed = Total distance travelled/time

= 240/26.666667

= 8.99m/s.

b. Total time = Total distance travelled / speed

= 240 / 9

= 26.66667sec.

Answer 2

$\sf{\underline{\boxed{\blue{\sf✧ Given :- }}}}$

• A man runs 120m at 6m/s.
• And again he covers 120m with a speed of 3m/s.

$\sf{\underline{\boxed{\blue{\sf✧To \: find :- }}}}$

• The average velocity.
• And total time taken.

$\sf{\underline{\boxed{\blue{\sf✧ Solution :- }}}}$

✯ For the first part :-

$\sf \: d1 = 120m. \: \\ \sf \: v(velocity) \: = 6m</strong><strong>/</strong><strong>s</strong><strong>. \\ \sf \: t1 = \frac{d1}{v} = \frac { \cancel{120}}{ \cancel6} \\ \sf = 20s$

✯ For the second one :-

$\sf \: d2 = 120 \: \: and \: v = 3m</strong><strong>/</strong><strong>s</strong><strong> \\ \sf \: t2 = \frac{d2}{3} = \frac{ \cancel{ 120}}{ \cancel3} = 40sec$

$\bf \therefore \: </strong><strong>T</strong><strong>otal \: displacement \: = d1 +d 2 \\ \sf = 120 + 120 = 240m. \\ \sf \therefore \: </strong><strong>T</strong><strong>otal \: time \: taken =( 40 + 20)sec = 60sec \\ \bf \therefore \: </strong><strong>Va</strong><strong>v = \frac{total \: distance}{ \: total \: time} = \frac{ \cancel{240}}{ \cancel{60}}</strong><strong>\</strong><strong>\</strong><strong> </strong><strong>\</strong><strong>s</strong><strong>f</strong><strong> </strong><strong>{</strong><strong>\</strong><strong>underline</strong><strong>{</strong><strong>\</strong><strong>b</strong><strong>o</strong><strong>x</strong><strong>e</strong><strong>d</strong><strong>{</strong><strong> </strong><strong>\</strong><strong>r</strong><strong>m</strong><strong>\</strong><strong>g</strong><strong>r</strong><strong>e</strong><strong>e</strong><strong>n</strong><strong> = 4m</strong><strong>/</strong><strong>s</strong><strong>}</strong><strong>}</strong><strong>}</strong><strong>$