As shown in figure, a $70\,kg$ garden roller is pushed with a force of $\overrightarrow{ F }=200\,N$ at an angle of $30^{\circ}$ with horizontal. The normal reaction on the roller is $.......\,N$ $\left(\right.$ Given $\left.g =10\,m s ^{-2}\right)$
$800 \sqrt{2}$
$600$
$800$
$200 \sqrt{3}$
If net force on a system is zero then
Two persons are holding a rope of negligible weight tightly at its ends so that it is horizontal. A $15\, kg$ weight is attached to the rope at the mid-point, which now no longer remains horizontal. The minimum tension required to completely straighten the rope is
Two objects $A$ and $B$ each of mass $m$ are connected by a light inextensible string. They are restricted to move on a frictionless ring of radius $R$ in a vertical plane (as shown in fig). The objects are released from rest at the position shown. Then, the tension in the cord just after release is
A car of mass $m$ when passes over top of convex bridge of radius of curvature $r,$ with a velocity $v,$ then the normal force exerted by the bridge on the car is
Two masses of $10 \,kg$ and $20 \,kg$ respectivety are connected by a massless spring as shown in fig. A force of $200 \,N$ acts on the $20 \,kg$ mass At the instant shown the $10 \,kg$ mass has acceleration $12 \,m / s ^2$ towards right. The acceleration of $20 \,kg$ mass at this instant is ........ $m / s ^2$