_____ extreme heat will vapourize the water inside a tree, creating steam that may burn out the tree.

Trees are greenish. They are greenish at the tip too.How does the water rise upward in a tree or plant against the force of gravity?

A student had a breakfast of 200 food calories. He thinks of burning this energy by drawing water from the well and watering the trees in his school. Depth of the well is about 25 m. The pot can hold 25 L of water and each tree requires one pot of water. How many trees can he water? (Neglect the mass of the pot and the energy spent by walking. ("Take g" = 10 ms^(-2))

Indian style of cooling drinking water is to keep it in a pitcher having porous walls. Water comes to the outer surface very slowly and evaporates .Most of the energy needed for evaporation is taken from the water itself and the water is cooled down. Assume that a pitcher contains 10kg water and 0.2g of water comes out per second. Assuming no backward heat transfer from the atmosphere to the water, calculate the time in which the temperature decreases by 5^(@)C . Specific heat capacity of water = 4200J kg^(-1).^@C^(-1) and latent heat of vaporization of water = 2.27 xx 10^(6)J kg^(-1)

Assertion (A) :No new substance is formed when water is heated to get steam. Reason (R) : Conversion of water into steam is a physical change.

Fill in the blanks: (i) Conductivity of water has resulted from the ____ of water. (ii) _____decomposition reaction may occur in the presence of heat or light.

A light rope fixed at one end of a wooden clamp on the ground passes over a tree branch and hangs on the other side. It makes an angle of 30^0 with the ground. A man weighing (60 kg) wants to climb up the rope. The wooden clamp can come out of the ground if an upward force greater than 360 N is applied it. Find the maximum acceleration in the upward direction with which the man can climb safely. Neglect friction at the tree branch. Take g=10 m/s^2

An empty plastic box of mass m is found to accelerate up at the rate of g/6 when placed deep inside water. How much sand should be put inside the box so that it may accelerate down at the rate of g/6?