Advertisements
Advertisements
प्रश्न
A bus was moving with a speed of 54 km/h. On applying brakes it stopped in 8 seconds. Calculate the acceleration.
Advertisements
उत्तर
(b) We have to find the value of uniform acceleration. So, Initial velocity
(u) = 54 km/hr
= `"54(1000)"/3600` m/s
= 15 m/s
Final velocity (v) = 0 m/s
Time taken(t) = 8 s
So acceleration, `a = (v-u)/t`
Put the values in the above equation to get the value of acceleration
`a = (0-15)/8`
= -`1.875 "m/s"^2`
APPEARS IN
संबंधित प्रश्न
Define velocity. What is the SI unit of velocity ?
Explain why, the motion of a body which is moving with constant speed in a circular path is said to be accelerated.
Derive the formula : v = u + at, where the symbols have usual meanings.
A train starting from stationary position and moving with uniform acceleration attains a speed of 36 km per hour in 10 minutes. Find its 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 body, initially at rest, starts moving with a constant acceleration 2 m s-2. Calculate: (i) the velocity acquired and (ii) the distance travelled in 5 s.
When is the positive acceleration?
Multiple choice Question. Select the correct option.
At the maximum height, a body thrown vertically upwards has :
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.
Draw a velocity versus time graph of a stone thrown vertically upwards and then coming downwards after attaining the maximum height.
