A body with mass 5 kg is acted upon by a force F = (3i + 4 hatj) N. If its initial velocity at t = 0 is v = 6i - 12hatj ms^(- 1) , the time at which it will just have a velocity along the Y-axis is

A body with mass 5 kg is acted upon by a force F = (3i + 4 hatj) N. If

1.	A body with mass 5 kg is acted upon by a force F = (3i + 4 hatj) N. If its initial velocity at t = 0 is v = 6i - 12hatj ms^(- 1) , the time at which it will just have a velocity along the Y-axis is
Answer» never 10 s 2 s 15 s Solution :10 s mass m = 5 kg force= F= `(3hat(j )+ 4hat(j )) N` Initialvelocityat t=0 ACCELERATION`vec( a ) = (vec( F))/(m )= ((-3hat(j)+ 4hat(j ))/( 5)` `v= u + at ` `=(6HAT(j)-12hat(j))+ ((-3)/( 5) hat(j ) + (4)/( 5)hat(j )) t` Finalvelocityis ALONG y -directionx - compof finalvelocity= 0 `(3t)/( 5 ) =6` `t= (5 xx 6)/(3 ) = 10 SEC`