Motion — Science STD 9 — Question

A body of mass 100kg is lifted up by 10m. Find:

1. The amount of work done.
2. Potential energy of the body at that height. (value of g = 10m/s).

What will be the residue left on the watch glass on heating blue ink in it?

Give one use each of the following radioactive isotopes:

1. Uranium-235
2. Cobalt–60

State one property in which a solution of sugar in water resembles a mixture of sugar and sand, and one property in which it differs from it.

What are the three groups into which all the elements can be divided? Name two elements belonging to each group.

A student placed a gas jar containing air in the upside down position over a gas jar full of red-brown bromine vapours. He observed that the red brown colour spread upwards into the jar containing air. Based on this observation, the student concluded that it is only the bromine vapour which moves up and diffuses into air in the upper jar, the air from the upper jar does not move down by diffusion into the lower jar containing bromine vapours. Do you agree with this conclusion of the student? Give reason for your answer.