12. HINT: use the concept tht change of momentum= F*t and hence find out the force
1)A lift is going upwards with an acceleration of 4.9 m/s2.Whatv will b the apparent wt. of a 60kg man in the lift?What when the lift rises up with a uniform velocity of 4.9m/s2?If the rope of the lift is broken,then?
2)A machine gun of mass 5 kg fires 30 bullets ,each of mass 50g,per min at a speed 0f 400m/s.What force must b exerted 2 keep the machine gun in posn?
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7 Answers
11.(i) acc. up then apparent wt. of man=90g
(ii) constant velocity apparaent wt.=60g
(iii) rope broken then apparent wt.=0
11N=m(g+a) [^ direction is +ve]
put a=g/2 ,0 , -g respectively...got it now??
1i m literally GOING TO SHOUT AT U madhurima now......i remember one MOSQUITO question u sent at the CB of mine to which i replied...then this question......i OBSERVED u don't reply to whether u got it or not....n just we see newer querstions from u.......arey bhaiya ham log answer karte hain toh WE TOO WANT TO KNOW IF U GOT IT N IF WE HAD GOT RIGHT ANSWER????.........next time u post any question remember to close tht discussion whether it be CHTBX or it be THREAD......got my point???
1@soham bhai are u sure wat u wrote up??? usko FORCE chahiye hai not recoil velocity :P