Advertisements
Advertisements
प्रश्न
The velocity-time graph (Fig. 8.5) shows the motion of a cyclist. Find (i) its acceleration (ii) its velocity and (iii) the distance covered by the cyclist in 15 seconds.
Advertisements
उत्तर
Velocity-time graph is a straight line parallel to the time axis, so, the velocity of the cyclist is constant.
(i) Acceleration = 0
(ii) At, f = 15 s velocity = 20 m s’1 (from the given graph)
(iii) Distance covered by the cyclist in 15 s
= Area under v - t graph during that time interval
= 20 ms’1 x 15 s
= 300 m.
APPEARS IN
संबंधित प्रश्न
Name the physical quantity whose SI unit is :
(a) m/s (b) m/s2
Fill in the following blank with a suitable word:
Acceleration is the rate of change of ______ It is measured in ______
Find the initial velocity of a car which is stopped in 10 seconds by applying brakes. The retardation due to brakes is 2.5 m/s2.
A bus running at a speed of 18 km/h is stopped in 2.5 seconds by applying brakes. Calculate the retardation produced.
A body starting from rest travels with uniform acceleration. If it travels 100 m in 5 s, what is the value of acceleration ?
The figure shows the displacement - time graph for four bodies A, B C and D. In each case state what information do you get about the acceleration (zero, positive or negative).
A stone thrown vertically upwards takes 3 s to attain maximum height. Calculate
- initial velocity of the stone
- maximum height attained by the stone. (Take g = 9.8 ms−2)
Draw a velocity versus time graph of a stone thrown vertically upwards and then coming downwards after attaining the maximum height.
An object starting from rest travels 20 m in the first 2 s and 160 m in the next 4 s. What will be the velocity after 7 s from the start?
Two stones are thrown vertically upwards simultaneously with their initial velocities u1 and u2 respectively. Prove that the heights reached by them would be in the ratio of `"u"_1^2 : "u"_2^2` (Assume upward acceleration is –g and downward acceleration to be +g)
