12> true .. mass is same .. velocity is same .. area of rails under these 2 is same ...
TRUE/FALSE
(1)
The pulley arrangements (a) and (b) are identical. THE ACCELERATION OF THE MASS m IS THE SAME IN BOTH CASES..
(2) Two identical trains are moving on rails alog the equator on the earth in opposite directions with the same speed. THEY WILL EXERT THE SAME PRESSURE ON THE RAILS..
(3) A simple pendulum has a bob of mass m and swings with an angular amplitude of 40°. WHEN IT'S ANGULAR DISPLACEMENT IS 20°, THE TENSION IN THE STRING IS GREATER THAN mgcos20°..
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17 Answers
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13exactly that.. force depends on the relative velocity between train and earth.....we get different values centrifugal force....
1so you mean to say force depends on the relative velocity between train and earth !!
11sorry, ankit.....while posting, i couldn't see what others were replying
And ur answer for 2 is wrong
1strider why dont u see my explaination above .. try to read the thread completely !!
11st false
acc of m in case a=mg/(m+2m)=mg/3m=g/3
in case 2 acc=mg/m=g
13.) true.
the centrifugal force will also act towards center.
so we need to take an outwards pseudo force .
13rd -> True .. because the bob has a velocity directed tangentially(edited by mistake i wrote radially , sorry for inconvinience ..) .. when angle is 20° .. this creates a force on the ball acting outwards ... now the wt. component of the ball is mgcos200 outwwards .. to balance both these forces .. T acts inwards and is greater than mgcos20°
11 -> false .. first case (2m - m)g/3m = g/3 .. .second (2mg - mg)/m = g