A simple pendulum with length 1.6 m and mass 21 kg is pulled 20◦ from the vertical and released. If it is allowed to swing until it comes to rest, how much energy was converted into heat? The acceleration of gravity is 9.8 m/s 2 . Answer in units of J

Mass (kg) force (n) 5 25 10 50 15 75 20 100 a student was trying to find the relationship between mass and force. he placed four different masses on a table and pulled them using a spring scale. the table shows the different masses used in the experiment and the force required to pull each mass. the student concluded that more force was required to pull heavier objects. what comment would you make regarding his conclusion? a) no clear relation can be observed between mass and force from the data. b) there is a direct proportion between the mass and force listed in the table. c) gravity should have been taken into account while performing the experiment. d) there is an inverse proportion between the mass and force listed in the table.

The diagram shows a series of volcanic island and a hot spot determine the direction of movement of the tectonic plate that for the island

Suppose a wire with a current is pushed upward by a magnetic field. how would the wire move if the direction of the current reversed? explain your answer.