Physics
An inclined plane makes an angle of 30° with the horizontal as shown in the figure. A box of mass 20 kg is taken from point A to point B along the inclined plane of length 2 m.
(a) Calculate the potential energy gained by the box.
(b) If 10 J of work is done against friction, in moving the box from A to B then calculate the force F needed to pull the block from A to B. [g = 10 m s-2]
Related Questions
A uniform metre ruler is balanced horizontally on a knife edge placed at 60 cm mark when a mass m is suspended from 75 cm mark. Draw the diagram of the arrangement. State with reason (through mathematical steps) whether the mass of the scale is greater than, less than or equal to the mass m?
State the energy conversions taking place:
(a) during photosynthesis
(b) in a thermocouple
(c) during bursting a cracker
The graph shows load against effort for a lever with load and effort on the same side of the fulcrum.
(a) Which attribute of the load vs effort graph must be calculated to determine the mechanical advantage?
(b) Which class does this lever belong to? How did you arrive at this conclusion?
(a) A man fires a gun and hears its echo after 3 s. The man then moves 80 m towards the hill and fires his gun again. This time he hears the echo after 2.5 s. Calculate the speed of the sound.
(b) State one reason of using ultrasonic waves in SONAR.