Q.1. Explain two-dimensional motion. Give two examples
of bodies possessing two-dimensional motion.
Q.2. Explain three-dimensional motion with examples.
Q.3. Discuss the position-time graph of an object at rest.
Q.4. Define (i) distance (ii) displacement. What are the
special features of 'displacement ?
Q.5. Distinguish between speed and velocity.
Q.6. Distinguish between average speed and average
velocity
Q.7. How can you determine average velocity from
displacement-time graph ?
Answers
Answer:
Q.1.Two dimensional motions are those which occur on a plane or whuch can be plotted using X-Y graph. Examples of such motions are :
i) A ball rolling on a ground.
ii) A car moving in arbitrary direction
Q.2. Motion in space where it can be plotted using X-Y-Z graph are called 3D motion. Ex:-
i) A space shuttle moving in space.
ii) A ball hit for a six.
Q.3. The line will be parallel to x-axis.
Q.4. i) Distance is the total path length covered due to the motion of a body. ii) Displacement is the shortest path between starting and end points. Its special features are that it is a vector quantity, it can be positive or negative or zero.
Q.5. Speed is the rate of change of distance whereas velocity is the rate of change of displacement. Speed is scalar whereas velocity is vector unit. Speed will always be positive but velocity will be '+' or '-' or 0.
Q.6. Average speed is the total distace divided by respective intervals of time. average velocity is the difference between final position and initial position divided by the corresponding time intervals
Q.7. Average velocity = x2 - x1 / t2 -t1