1. Motion is relative or absolute? Give reason.
2. Name the physical quantity that essentially changes as a body moves. 3. Is displacement or distance independent of path? How?
4. Give example of a motion in which distance is covered but there is no displacement. 5. Give one example of motion where, distance and displacement are same. 6. When moving car returns to the same point what will be the ratio of a) Displacement to distance.
b) Distance to displacement.
7. In a long distance race, the athletes take four rounds of a track such that the time of Finish is same as the line of start. The length of the track is 200 m. a) What is the total distance covered by the athletes?
b) What is the displacement when they touch the finish line? c) Is the motion uniform or non-uniform?
d) Is the displacement and distance moved by the athletes at the end of the race equal? Why? 8. A man walks 5m in north direction and turns left to move 12m. What is the a) Distance,
b) Displacement associated with the movement?
9. A man keeps 12 steps in north direction and turns right to keep 5 steps. He then returns to the initial point by the shortest path. Find a) Distance travelled.
b) Displacement. Given step is 0.4m.
10.A circular cycle track has a circumference of 308m (ABCDA) with AC as one of its diameter. A cyclist travels from A to D along the circular path. Find the distance moved by the cyclist and the displacement if AB is along west-east direction. B
A A C
11. If 5m/s and 10m/s are the velocities of a body having a uniform acceleration in some time interval, what will be its average velocity? 12. A train travels from station A to station B with a speed of 36km/h and returns to A with a speed of 54km/h. What is the average velocity and average speed of travel? 13. A car travels with a velocity of V1m/s for S-m and with V2m/s for another S-m. What is the average velocity in the straight-line motion? 14. A train travels at a speed of 60 km/h for 0.52h, at 30km/h for the next 0.24h and then at 70km/h for the next 0.71h. What is the average speed of the train?
PROBLEM SOLVING ASSESSMENT
We define power as the rate at which work is done. The power spent by a source is measured as the amount of work done per sec by a source or it is numerically equal to the work done by a source in one second. It is a scalar quantity
If a lift takes 1 minute to lift ‘a’ load to another floor, while another lift ‘b’ takes 2 minutes to lift the load to the same floor, then work done by both the lifts would be same, but the power spent by lift ‘a’ is twice the power spent by ‘b’ because work is done at a faster rate by lift ‘a’. 1. On which of the following factors does power depend?
2. Ajay can transfer a suitcase which weighs about 35 kg, from one room to another in 10 sec. Vijay does the same job in 30 sec. which of the following statements is correct? A) Power spent by Ajay is thrice Vijay
B) Power spent by Vijay is thrice the power spent by Ajay C) Both have spent equal powers.
D) None of these.
3. If work is represented by u, temperature by v, momentum by x, time taken by y, and power by z, which one of the following is correct? A) Z=uvx/y
4. Calculate the power of the engine which does a work of 5500 j in two minutes and 5 seconds. A) 44 W
B) 44.5 W
C) 73 W
D) 110 W
A long time ago, a boy, later became one of the greatest scientists who dominated several fields, was wondering why...