Which car has the highest kinetic energy if each car is traveling at a speed of 1 m/s? Explain how you arrived at your answer. Car a is going 2 KG
Car B 4KG
Car c 6KG
Car D 8KG

Car D

Because it is the heaviest. Kinetic energy is directly proportional to the velocity and mass of the object. All the cars have the same velocity. But Car D has the most mass. So, it has most kinetic energy, because more the mass more the energy.

a mercury barometer is a device that uses the physical properties of mercury in a tube to measure barometric pressure. mercury barometers are used for : -

1. measurement of atmospheric pressure  

2. determining the altitude of a place

3. weather forecasting

4. calibration and checking of aneroid barometers

5. application in fluid mechanics

6. measurement of pressure in aircrafts

7. surface weather analysis

8. preparation of barographs

9. usage in physical sciences like physics, astronomy & chemistry

10. preparation of aircraft altimeters

characteristics of mercury barometer : -

1.used to define and measure atmospheric pressure.

2.on the average at sea level the column of mercury rises to a height of about 760 mm.

3.this quantity is equal to 1 atmosphere.

4.it is also known as standard atmospheric pressure.

5.a barometer in which the weight of a column of mercury in a glass tube with a sealed top is balanced against that of the atmosphere pressing on an exposed cistern of mercury at the base of the mercury column, the height of the column varying with atmospheric pressure.

i have no clue hope you find the answer