Which statement is a scientifically accurate description of velocity? 1. The boat traveled from the dock north to the 200-meter marker in the bay in less than 5 minutes, giving the passengers several more hours to fish.

2. Walking south along the two-mile canyon trail generally takes less time than traveling the same trail north because walking south is all downhill.

3. The hiker began hiking the park's five-mile north hiking trail at 8:00 a. m. with plenty of daylight left to complete the hike before dark.

4. The motorcyclist traveled along a highway at 55 mph and reached the campsite in less than the two-hour estimated time.

The motorcyclist traveled along a highway at 55 mph and reached the campsite in less than the two-hour estimated time.

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.