A block of mass $1\, kg$ is at rest on a horizontal table. The coefficient of static friction  between the block and the table is $0.5.$ The magnitude of the force acting upwards at  an angle of $60^o$ from the horizontal that will just start the block moving is
Medium
Download our app for free and get startedPlay store
$\mathrm{N}=\mathrm{mg}-\frac{\sqrt{3} \mathrm{F}}{2}$

If block just starts moving

$\mathrm{F} \cos 60^{\circ}=\mu \mathrm{N}$

$\Rightarrow \frac{\mathrm{F}}{2}=0.5\left(\mathrm{mg}-\frac{\sqrt{3}}{2} \mathrm{F}\right)$

$\Rightarrow \mathrm{F}+\frac{\sqrt{3} \mathrm{F}}{2}=10$      or     $F=\frac{20}{2+\sqrt{3}}$

art

Download our app
and get started for free

Experience the future of education. Simply download our apps or reach out to us for more information. Let's shape the future of learning together!No signup needed.*

Similar Questions

  • 1
    A car has to move on a level turn of radius $450\,m.$ If the coefficient of static friction between tyre and the road is $\mu  = 0.2.$ Find the maximum speed the car can take without skidding is given by ........ $m/s$
    View Solution
  • 2
    A body is sliding down an inclined plane having coefficient of friction $0.5$. If the normal reaction is twice that of the resultant downward force along the incline, the angle between the inclined plane and the horizontal is ....... $^o$
    View Solution
  • 3
    For a body moving in a circular path, a condition for no skidding if $\mu $ is the coefficient of friction, is
    View Solution
  • 4
    A body is sliding down an inclined plane (angle of inclination $45^o$). If the coefficient of friction is $0.5$ and $g = 9.8\, m/s^2$. then the acceleration of the body downwards in $m/s^2$ is
    View Solution
  • 5
    A boy of mass $4\, kg$ is standing on a piece of wood having mass $5 \,kg$. If the coefficient of friction between the wood and the floor is $0.5,$ the maximum force that the boy can exert on the rope so that the piece of wood does not move from its place is ......$N.$(Round off to the Nearest Integer) [Take $g=10 \,ms ^{-2}$ ]
    View Solution
  • 6
    Determine the time in which the smaller block reaches other end of bigger block in the figure. $(g = 10\ m s^{-2})$ .......... $\sec$
    View Solution
  • 7
    On a railway curve, the outside rail is laid higher than the inside one so that resultant force exerted on the wheels of the rail car by the tops of the rails will
    View Solution
  • 8
    A train is moving with a speed of $12 \mathrm{~m} / \mathrm{s}$ on rails which are $1.5 \mathrm{~m}$ apart. To negotiate a curve radius $400 \mathrm{~m}$, the height by which the outer rail should be raised with respect to the inner rail is (Given, $g=$ $10 \mathrm{~m} / \mathrm{s}^2$ ) :
    View Solution
  • 9
    $STATEMENT-1$ It is easier to pull a heavy object than to push it on a level ground. and

    $STATEMENT-2$ The magnitude of frictional force depends on the nature of the two surfaces in contact.

    View Solution
  • 10
    The tension $T$ in the string shown in figure is
    View Solution