Akshit_math 2 years ago A rocket is fired vertically from the ground. It moves upwards with a constant acceleration of 10m/s^2 for 30 seconds, after which the fuel is consumed. After what time from the instant of firing, the rocket will attain the maximum height? (Take g=10m/s^2)

1. Mashy

calculate the velocity of the rocket after 30 seconds.. !.. and then use your 1d kinematics to solve the problem..

2. Akshit_math

@Mashy here will the intitial velocity be taken 0??..

3. Akshit_math

here the options are given as 75s , 60s , 45s and 30s...so what should be the answer according to u?

4. Mashy

yes.. you have to take the initial velocity as zero.. and then compute the velocity after 30 seconds.. using 10m/s^2 uniform acceleration.... then do another computation by taking that newly computed velocity as the initial velocity and find time for max height.. !!

5. Akshit_math

ohhhh...ok...let me first try that out...

6. Mashy

yea.. sure :).. if you don't get the answer.. show me your work here! .. ll tell whats wrong

7. Akshit_math

in the another calculation...i should take the acceleration as that g=10m/s^2...and in that one i should take the final velocity as 0 ..?,,,right?..

8. Akshit_math

if in the second case i tak final velocity 0 ...then i get answer as 30 s ..easily..?.