The tension $T$ in the string shown in figure is
Zero
$50\, N$
$35 \sqrt 3\,\ N$
$(\sqrt 3 -1) 50\,N$
A block of mass $m$ is moving with a constant acceleration a on a rough plane. If the coefficient of friction between the block and ground is $\mu $, the power delivered by the external agent after a time $t$ from the beginning is equal to
Which one of the following is not used to reduce friction
When a bicycle is in motion, the force of friction exerted by the ground on the two wheels is such that it acts
A heavy body of mass $25\, kg$ is to be dragged along a horizontal plane $\left( {\mu = \frac{1}{{\sqrt 3 }}} \right).$ The least force required is ........ $kgf$
Pulling force making an angle $\theta $ to the horizontal is applied on a block of weight $W$ placed on a horizontal table. If the angle of friction is $\alpha $, then the magnitude of force required to move the body is equal to