An object initially moving north has a constant net force directed to the east. Which of the following best describes the work done by the net force? The net force does no work to the object The net force does positive work to the object and velocity of object is constant. The net force does positive work to the object and velocity of object is increasing.

X A 10 Kg object is raised to a height of 2m in 5s. What is the rate of work done? * 10 W- 10 メ 10 -100 15 O 20 - 1000 40

Which do you think requires more work: moving up stairs at a slow speed (ex: walking) or moving up stairs at a fast speed (ex: running)? Explain your prediction with reference to the work equation and some past experience.

Question 9 What does it mean when an object has positive work done on it by a force? Energy is flowing out of the object. Energy is flowing into the object. O The object's energy is not changing. Question 10 What does it mean when an object has negative work done on it by a force? The object's energy is not changing. Energy is flowing out of the object. Energy is flowing into of the object.

An object is displaced by 0.5m against a force of friction at 2N. What is the work done on the object by the friction? -6J 1J -1J 4J

Explain how you know there is work being done on an object?

We know from the reading that it is possible to move the same object two different distances and still do the same amount of work. Let's consider an example in which Jane pushes a block of ice up an incline while Kip lift the same block of ice vertically to the top of the same incline. See the figure below. (look at picture) We will assume that there is no friction between the surface of the incline and the block of ice. Both of these situations will require the same amount of work and that the result of lifting the ice block to some height imparts potential energy to the ice. In this activity, we will make various calculation to help us better understand the relationship between work and potential energy and the idea of conservation of energy. For this activity we will assume that the mass of the ice block is 5.6 kg and the vertical height of the incline is 2 m. This is the vertical distance that Kip must lift the block of ice. We will assume that the acceleration due to gravity is 10…

a) Calculate the work done when a 5.0 kg bag of apples is lifted 1.2 off the ground.  b) If this bag of apples is carried at this height to the checkout counter, is any work done? Justify your choice.  c) Calculate the power developed when the action of lifting the apples takes 2.0 s.

The figure below shows an overhead view of two horizontal forces pulling a box along the floor. How much work does each force do as the box is displaced 70 cm along the broken line. What is the total work done by the two forces in pulling the box this distance?