X-rays — Physics STD 11 Science — Question

A particle is projected in air at some angle to the horizontal, moves along parabola as shown in Fig., where x and y indicate horizontal and vertical directions, respectively. Show in the diagram, direction of velocity and acceleration at points A, B and C.

A constant force of 2.50N accelerates a stationary particle of mass 15g through a displacement of 2.50m. Find the work done and the average power delivered.

A trolley of mass 300kg carrying a sandbag of 25kg is moving uniformly with a speed of 27km/h on a frictionless track. After a while, sand starts leaking out of a hole on the floor of the trolley at the rate of 0.05 kgs^-1. What is the speed of the trolley after the entire sand bag is empty?

The condition of air in a cloeed room is described as follows. Temperature = 25°C, relative humidity = 60%, pressure = 104kPa. lf all the water vapour is removed from the room without changing the temperature, what will be the new pressure? The saturation vapour pressure at 25°C = 3.2kPa.

A motor boat covers the distance between two spots on the river in time of 8hrs. and 12hrs. downstream and upstream respectively. What is the time required for the boat to cover this distance in still water?

Derive an expression for the orbital velocity of a satellite in the orbit. Reduce it to an orbit close to the surface of earth. How is it related to escape velocity?

Find an expression for the orbital velocity of a satellite revolving around the earth in a circular orbit at a height h above the surface of earth.

A man walks on a straight road from his home to a market 2.5km away with a speed of 5km ^h–1. Finding the market closed, he instantly turns and walks back home with a speed of 7.5km h^–1. What is the
Average speed of the man over the interval of time

1. 0 to 30 min,
2. 0 to 50 min,
3. 0 to 40 min?

[Note: You will appreciate from this exercise why it is better to define average speed as total path length divided by time, and not as magnitude of average velocity. You would not like to tell the tired man on his return home that his average speed was zero!]

A body of mass ‘m' suspended from a spring executes S.H.M. Calculate the ratio of the kinetic energy and potential energy of the body when it is at half the amplitude far from the mean position.

Estimate the moment of inertia for a disc of radius R and mass M about an axis passing through its centre and perpendicular to its plane.