The projection of the line segment joining $\mathrm{P}(2,-1,0)$ and $\mathrm{Q}(3,2,-1)$ on the line whose direction ratios are $1,2,2$ is

The percentage error in the measurement of mass and speed of a particular body is $3 \%$ and $4 \%$ respectively. The percentage error in the measurement of kinetic energy is

A car is driven on the banked road of radius of curvature 20 m with maximum safe speed. In order to increase its safety speed by $20 \%$, without changing the angle of banking, the increase in the radius of curvature will be [Assume friction is same on the road]