if you grow a potted plant that initially weighed 200 g and eventually weighed 50 kg, would you expect the soil in the pot to change weight? Explain.

A radioactive substance is oxidised. What changes would you expect to take place in the nature of radioactivity ? Explain your answer.

Given below is the diagram of an experimental set-up to study the process of transpiration in plants. Study the same and then answer the questions that follow : After about half an hour what change, if any, would you expect to find in the cobalt chloride papers placed on the dorsal and ventral sides of the leaf? Give a reason to support your answer.

In a plant, two genes have cumulative influence on the weight of fruits. Each dominant allele adds 10g to a minimum basic weight of 30g. In a cross between dihybrid plants having fruits weighing 50g each, what percentage of the offspring would have fruits weighing 40g :-

A person normally weighing 60 kg stands on a platform which oscillates up and down harmonically at a frequency 2.0 sec^(-1) and an amplitude 5.0 cm . If a machine on the platform gives the person's weight against time deduce the maximum and minimum reading it will shown, Take g = 10 m//sec^(2) .

A man wants to draw a bucket full of water in two different ways. As shown in figure 'a' he draws the bucket directly and as shown in figure (b) he uses a pulley. The weight of the man is 50kg and the bucket with full water weighs 25kg. Find the action on the floor by the man in the two cases. (Take g=10ms^(-2) ).

GM plants are useful in many ways. How would you convince farmers to grow GM plants on their field ? Explain giving three reasons.

Direction : Resistive force proportional to object velocity At low speeds, the resistive force acting on an object that is moving a viscous medium is effectively modeleld as being proportional to the object velocity. The mathematical representation of the resistive force can be expressed as R = -bv Where v is the velocity of the object and b is a positive constant that depends onthe properties of the medium and on the shape and dimensions of the object. The negative sign represents the fact that the resistance froce is opposite to the velocity. Consider a sphere of mass m released frm rest in a liquid. Assuming that the only forces acting on the spheres are the resistive froce R and the weight mg, we can describe its motion using Newton's second law. though the buoyant force is also acting on the submerged object the force is constant and effect of this force be modeled by changing the apparent weight of the sphere by a constant froce, so we can ignore it here. Thus mg - bv = m (dv)/(dt) rArr (dv)/(dt) = g - (b)/(m) v Solving the equation v = (mg)/(b) (1- e^(-bt//m)) where e=2.71 is the base of the natural logarithm The acceleration becomes zero when the increasing resistive force eventually the weight. At this point, the object reaches its terminals speed v_(1) and then on it continues to move with zero acceleration mg - b_(T) =0 rArr m_(T) = (mg)/(b) Hence v = v_(T) (1-e^((vt)/(m))) In an experimental set-up four objects I,II,III,IV were released in same liquid. Using the data collected for the subsequent motions value of constant b were calculated. Respective data are shown in table. {:("Object",I,II,II,IV),("Mass (in kg.)",1,2,3,4),(underset("in (N-s)/m")("Constant b"),3.7,1.4,1.4,2.8):} If buoyant force were also taken into account then value of terminal speed would have

Shyam planted a flowering plant in an earthen pot and he then irrigated it well. In order to make the plant grow faster, he added a considerable amount of urea in the earthen pot. After some time he observed that the plant died. Could you explain the beyon?

A body weight 50 g in air and 40 g in water. How much would it weigh in a liquid of specific gravity 1.5?

Kanchan bought a watermelon weighing 5 kg 200 g. Out of this she gave 2 kg 750 g to her neighbour. What is the weight of the watermelon left with Kanchan?