Question

an object covers a distance of 400 m with a velocity of 20m/s,and covers next 600m in time 20 sec.find average velocity of yhe object

Answer 1

Case 1:-

Distance Covered = 400 m

Velocity = 20m/sec

Time = distance/speed

Time = 400/20 = 20 seconds

$\rule{200}{2}$

Case 2 :-

Distance covered = 600 m

Time taken = 20 seconds

$\rule{200}{2}$

Total Distance covered = 400+600 = 1000m

Total time taken = 20+20 = 40 seconds

Thus,

Average Velocity will become :-

$=\dfrac{1000}{40}\\ \\ \\=\dfrac{100}{4}\\ \\ \\=25m/sec$

$\rule{200}{2}$

Answer 2

Answer:

Average Velocity :

Distance covered, $\mathsf{s_1}$ = 400 m

Velocity for 400m distance , v = 20 m/s

Time, $\mathsf{t_1}$ = $\mathsf{\dfrac{400} {20}}$

Time, $\mathsf{t_1}$ = 20 s

Distance covered in next 20 s, $\mathsf{s_2}$ = 600 m

For average velocity of the object,

$\mathsf{V_{avg}}$ = $\mathsf{\dfrac{Total\: Distance} {Total\: time}}$

$\mathsf{V_{avg}}$ = $\mathsf{\dfrac{s_2 \: + \: s_1} {20 \:+\:20 }}$

$\mathsf{V_{avg}}$ = $\mathsf{\dfrac{600 \: + \:400} {40}}$

$\mathsf{V_{avg}}$ = $\mathsf{\dfrac{1000} {40}}$

$\mathsf{V_{avg}}$ = 25 m/s.