lift an object up, muscular force and gravity act on it, i) which one of these forces is doing a positive work and why? ii) which one of theseis doing a negative work and why?
Answers
Answer:
Answer:
Explanation:
When a force is applied to an object, the result is typically an acceleration in the direction of the net force. By making an object accelerate, we are changing the amount of energy it has. Energy is the ability to do work or accomplish a task.
By applying a force on a ball when we throw it, we are giving it the ability to travel through the air, and the ability to make a dent in the dirt when it lands. The ball would not have been able to do those things without the transfer of energy from your hand to the ball.
It is easy to imagine that the bigger the initial force on the ball, the greater the amount of energy it has - the farther it will be able to travel through the air, or the deeper the dent it will make in the dirt when it lands. Indeed, the huge force used by a bow to accelerate an arrow gives the arrow enough energy to embed itself deep within a target.
In this activity, we will be looking at different types of energy, and how we can measure the transfer of energy from one object to another.
Also because force is measured in newtons, and displacement is measured in metres, work is measured in newton-metres. This unit is given a special name: joules (J). Note that although force and displacement are vector quantities, work is a scalar quantity. The vector notation disappears as a result of the dot operator (∙) used to multiply the two vectors. The symbol for work (W) is very similar to the symbol for weight (\vec{W}) - the difference being that weight is a vector quantity so we add the vector notation of the arrow, while work is a scalar quantity. Be careful to not mix up the two.
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Answer:when we lift an object two forces acts on the object mucuar on the force doing poisitive work on the gravitaional force ,doing negetive work on the work to its opposite direction of the work
Explanation: