A man is driving a car. He slows down to stop at a stop sign. When does the car have the most kinetic energy (KE)?

When the car's speed is 30 miles per hour

When the car's speed is 15 miles per hour

When the car's speed is miles per hour

The car's motion energy is the same the whole time

the answer is a for sure mark brainliest i had got this right on usatestprep

answer : third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol

explanation :

let us write down the given equations

equation 1 :

equation 2 :

equation 3 :

let us use hess's law to find out which 2 equations can be added to get the third equation.

let us reverse equation 2 and multiply it by 2. the new equation that we get is,

equation 4 :

let us add equation 1 & 4

the above equation is similar to equation 3 but has different value for dhrxn.

therefore third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol