A heater core is a radiator-like device used in heating the cabin of a vehicle. Hot coolant from the vehicle's engine is passed through a winding tube of the core, a heat exchanger between coolant and cabin air.
Explanation:
Explanation:
Step1
Factor of safety is the number that is taken for the safe design of any component. It is the ratio of failure stress to the maximum allowable stress for the material.
Step2
It is an important parameter for design of any component. This factor of safety is taken according to the environment condition, type of material, strength, type of component etc.
Step3
Different material has different failure stress. So, ductile material fails under shear force. Ductile material’s FOS is based on yield stress as failure stress as after yield point ductile material tends to yield. Brittle material’s FOS is based on ultimate stress as failure stress.
The expression for factor of safety for ductile material is given as follows:

Here,
is yield stress and
is allowable stress.
The expression for factor of safety for brittle material is given as follows:

Here,
is ultimate stress and
is allowable stress.
Answer:
correct option is c. a testable prediction leading to design of an experiment
Explanation:
The results of raising tadpoles were estimated to be water with an atrazine level of 0.1 ppb compared to those grown in pure water. So, this is not the question. If this assumption can now be tested, an experiment can be made in which a certain number of tadpoles can be raised in pure water and the same number of tadpoles can be raised in water with a 0.1ppb atrazine level can. The difference between the two populations can be estimated or compared.
Answer:
Correct option: B. 90%
Explanation:
The confidence interval is given by:
![CI = [\bar{x} - z\sigma_{\bar{x}} , \bar{x}+z\sigma_{\bar{x}} ]](https://tex.z-dn.net/?f=CI%20%3D%20%5B%5Cbar%7Bx%7D%20-%20z%5Csigma_%7B%5Cbar%7Bx%7D%7D%20%2C%20%5Cbar%7Bx%7D%2Bz%5Csigma_%7B%5Cbar%7Bx%7D%7D%20%5D)
If
is 190, we can find the value of
:



Now we need to find the value of
:


So the value of z is 1.71.
Looking at the z-table, the z value that gives a z-score of 1.71 is 0.0436
This value will occur in both sides of the normal curve, so the confidence level is:

The nearest CI in the options is 90%, so the correct option is B.