Advertisements
Advertisements
प्रश्न
A bus running at a speed of 18 km/h is stopped in 2.5 seconds by applying brakes. Calculate the retardation produced.
Advertisements
उत्तर
We have to find the value of retardation. So,
Initial velocity,
`(u)` = 18 km/hr
= `"18(1000)"/3600` m/s
= 5 m/s
Final velocity, (v) = 0 m/s
Acceleration , `a = (v-u)/t`
Put the values in the above equation to get the value of acceleration
`a = (0-5)/2.5`
= `-2 "m/s"^2`
Thus, the retardation is 2 m/s2.
APPEARS IN
संबंधित प्रश्न
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.
Describe the motion of a body which is accelerating at a constant rate of 10 m s–2. If the body starts from rest, how much distance will it cover in 2 s ?
A cheetah starts from, rest, and accelerates at 2 m/s2 for 10 seconds. Calculate :
(a) the final velocity
(b) the distance travelled.
A body starting from rest travels with uniform acceleration. If it travels 100 m in 5 s, what is the value of acceleration ?
Derive the formula s= `ut+1/2at^2` , where the symbols have usual meanings.
A bicycle initially moving with a velocity 5.0 m s-1 accelerates for 5 s at a rate of 2 m s-2. What will be its final velocity?
A body is thrown vertically upward with velocity u, the greatest height h to which it will rise is,
A girl walks along a straight path to drop a letter in the letterbox and comes back to her initial position. Her displacement–time graph is shown in Fig.8.4. Plot a velocity-time graph for the same.
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.
Draw a velocity versus time graph of a stone thrown vertically upwards and then coming downwards after attaining the maximum height.
