Technician a says that oat type coolant should be changed every 2 years. technician b says that iat type coolant should be changed every 2 years. which technician is correct?

Technician B is correct i-e IAT type coolant should be changed every 2 years.

Explanation:

Coolant is one of the most important fluid for the car as it prevents the engine from overheating during summers and freezing during winters. What it does is that it actually lowers the freezing point during summers and increases the boiling point of the system during summers. There are different types of coolant used by different cars. Among which, two of them are:

1)OAT i-e Organic Acid Technology

2)IAT i-e Inorganic Additive Technology  

IAT type coolants are usually used by older cars and generally should be usually replaced every 2 years. While, the other type which is the OAT type coolant should be replaced every 5 years.

Thus, Technician B is correct i-e IAT type coolant should be changed every 2 years.

Now for this problem, what is given is a 40 Newtons which would represent the force to be applied to the object, and a distance of 10 meters after the application of the said force. When these two combine, work is done. The unit for work is Joules and this is what we are looking for. The formula to get Joules or for work would be the force applied to the object multiplied by the distance that it travelled after the application of the force. It looks like this

work = force x distance
Joules = Newtons x meter

so let us substitute the variables to their corresponding places

Joules = 40 N x 10 m
Joules = 400 J

So the answer to this question would be C. 400 J