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.
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
Fill in the following blank with suitable word :
A motorcycle has a steady……………. of 3 m/s2. This means that every………………. its…………….. increases by………….
Define velocity. What is the SI unit of velocity ?
Fill in the following blank with suitable word :
If a body moves with uniform velocity, its acceleration is ..............
A boy is sitting on a merry-go-round which is moving with a constant speed of 10 m s−1. This means that the boy is :
When is the positive acceleration?
Multiple choice Question. Select the correct option.
A body dropped from the top of a tower reaches the ground in 4s. Height of the tower is
A packet is dropped from a stationary helicopter, hovering at a height ‘h’ from ground level, reaches the ground in 12s. Calculate
- the value of h
- final velocity of packet on reaching the ground. (Take g = 9.8 ms−2)
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)
Area under a v – t graph represents a physical quantity which has the unit
When will you say a body is at uniform acceleration?
