Physics, asked by hritikroshan204, 8 months ago

a truck is running on a highway at the speed of 70km/h. as soon as the drivers sees a cow at a distance of 300m on the road, he applies the brakes but was not able to save the cow. his truck stop at 700m. calculate the time at which he hit the cow and when he stopped if it at the moment he saw the cow is taken as the starting time.Also find the retardation to save the cow

Answers

Answered by PRIYANKA9810

Initial velocity of lorry, u= 10 m/s

Initial distance of cow from lorry, D= 50 m

Final velocity of lorry, v= 0 m/s

(Since, driver stops the lorry)

Acceleration of truck, a= -1.25 m/s²

(Since, acceleration is opposite to retardation in sign but have same magnitude)

Reaction time of driver, t'= 0.5 s

To Find:

Possibility that lorry will hit cow or not

Solution:

We know that,

According to third equation of motion for constant acceleration,

where,

v is final velocity

u is initial velocity

a is acceleration

s is displacement

Let the distance travelled by lorry before the driver applied the brake be d'

So,

Let the distance travelled by lorry after applying brake be d

So, on applying third equation of motion on lorry, we get

Now, let total distance covered by lorry after driver sees the cow be S

So,

Now let us calculate D-S

This shows that lorry will stops 5 m before the cow.

Since, the initial distance between lorry and cow is greater than the total distance travelled by lorry after driver sees the cow.

Hence, the lorry will not hit the cow.

Answered by BrainlyNisha001

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