Question

a car travels 72km/h with uniform acc. 2m/s^2?find dist. it goes before a stop?and time it taken to stop? and dist.it travels during the 1st and 2nd sec.

Answer 1

HEYA!!!

YOUR ANSWER:
u= 72 km/hr
v= 0
a= (-2m/s^2) {retardation}

72km/hr = 72×1000/3600
= 20m/s

Now, we have the equation:

$v = u + at$

And by using it, we get:

$0 = 20 + ( - 2t )\\ = > - 20 \div - 2 = t \\ = > 10s = t$

Therefore, time is 10 seconds.


Now, by using the identity:

$s = ut + 1 \div 2a {t}^{2}$

Solving it:

$s = 200 + ( - 200) \div 2 \\ = 200 - 100 \\ = 100m$

Therefore, distance is 100m.

Now,
Distance travelled in 10s = 100m
Distance travelled in 1s = 100/10
= 10m
Distance travelled in 1st n 2nd seconds = 10 + 10
= 20m

HOPE IT HELPS!!!!
SO SORRY FOR THE DELAY!!