$A$ person moves from $A$ to $B$ on a circular path as shown in the figure. If the distance travelled by him is $60 \, m$,then the magnitude of the displacement would be $..... \, m$. (Given $\cos 135^{\circ} = -0.7$)

$A$ body of mass $m$ is projected from the ground with speed $u$ at an angle $\theta$ with the horizontal. The power delivered by gravity to it at half of the maximum height from the ground is

$A$ projectile is thrown into air with velocity $15 \ m/s$ at an angle $30^{\circ}$ with the horizontal. After what time is its direction of motion perpendicular to its initial direction (in $s$)? (Assume $g = 10 \ m/s^2$)

$A$ particle has an initial velocity $(3\hat{i} + 4\hat{j})$ and an acceleration of $(0.4\hat{i} + 0.3\hat{j})$. Its speed after $10\,s$ is:

$A$ particle of mass $m$ moves with constant speed $v$ on a circular path of radius $r$ as shown in the figure. The average force on it during its motion from $A$ to $B$ is

$A$ body projected along a frictionless inclined plane of angle of inclination $30^{\circ}$ covers a distance of $40\, m$ along the plane. If the body is projected with the same speed at an angle of $30^{\circ}$ with the ground,it will have a range of: (Take $g = 10\, m/s^2$)