A block of mass $1 \mathrm{kg}$ and density $0.8 \mathrm{g}/{\mathrm{cm}}^3$ is held stationary with the help of a string as shown in figure. The tank is accelerating vertically upwards with an acceleration $\mathrm{a}=1.0 \mathrm{m}/{\mathrm{s}}^2$. Find

the tension in the string,

(Take $\mathrm{g}=10 \mathrm{m}/{\mathrm{s}}^2$ and density of water $={10}^3 \mathrm{kg}/{\mathrm{m}}^3$ ).