SCALAR VECTOR QUANTITIES

Mass, length, time, area, velocity and acceleration – all of these quantities are physical ones. Whenever we measure one of these quantities we are finding its magnitude. For example,

“30 miles” is a measurement of a distance. “30 miles west” is a measurement of displacement.

Both have a magnitude of 30 miles. However, the displacement also includes the direction in which it is measured.”30 mph” is a measurement of speed. “20 mph south-west’ is a measure-ment of velocity. Both speed and velocity have magnitudes. Which of two has direction (speed or velocity)? “35 mph west” is a velocity. “30 miles west “is a displacement. Quantities which have magnitude only are scalar quantities, while vector quantities have magnitude and direction.

Mass, volume, area and intervals of time have magnitude only. They are scalar quantities.

Force, velocity and acceleration have magnitude and direction. They are vector quantities.

P. Match each of terms in list A with quantities in list B.

1. velocity, speed, displacement, magnitude, direction.
2. 30 miles, 30 miles north, 30 min/hr north, 30 min/hr, north.

Q. Which of these magnitudes are scalar or vector?

90 ft / sec north, 47 miles, 15 cm, 14 mph.

R. Fill gaps with the appropriate words.

1. Quantities which are scalar have ………….. only.

2. Mass, volume, area, intervals of time have magnitude only. They are ……..

3. Quantities which have both magnitude and direction are ……….. quantities.

4. Force, velocity and acceleration have magnitude and ……….. .They are ……… .

5. The measurement of a scalar quantity consists of ……………. .

6. The measurement of a vector quantity consists of ……………. and ……….. .

S. Discuss the different systems of measurements, kinematics, scalar and vector quantities,

describe their advantages and disadvantages, prepare a short summary to the lesson 2.

Date: 2014-12-28; view: 1944