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A two stage rocket is fired vertically u...


A two stage rocket is fired vertically upward from rest with acceleration as shown in a-t graphs. After 15 sec, the first stage burns out and second stage ignites. Choose the INCORRECT statement regarding motion of rocket in the time interval `0letle40s`.

A

at t=15 sec, the speed of rocket is 15.0m/s

B

At t=20 sec, the speed of rocket is 300m/s

C

In time interval t=0 sec to t=15 sec, the distance travelled by rocket is 750 m.

D

in time interval t-0 sec to t=20 sec, the distance travelled by rocket is 1500 m.

Text Solution

Verified by Experts

The correct Answer is:
D
`v{{:((2t^(2))/(9)hatj,"if "0letle15sec),(150+150(5-15)+15(t-15)^(2)hatj,"if "15sletle40s):}`
at t=15
`r=(2xx15xx15xx15)/(3xx3)=750m`
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