The SI unit of a physical quantity is pascal-second. The dimensional formula of this quantity will be :

The distance of the Sun from earth is 1.5 $$\times$$ 10¹¹ m and its angular diameter is (2000) s when observed from the earth. The diameter of the Sun will be :

When a ball is dropped into a lake from a height 4.9 m above the water level, it hits the water with a velocity v and then sinks to the bottom with the constant velocity v. It reaches the bottom of the lake 4.0 s after it is dropped. The approximate depth of the lake is :

One end of a massless spring of spring constant k and natural length l₀ is fixed while the other end is connected to a small object of mass m lying on a frictionless table. The spring remains horizontal on the table. If the object is made to rotate at an angular velocity $$\omega$$ about an axis passing through fixed end, then the elongation of the spring will be :