Answer:
2) center mass
3) when work is done by a system, energy is released
Explanation:
Answer: Friction
Explanation:
Friction is a force that opposes the motion of an object on another surface. For example, when a box is pushed along the floor, the floor exerts a frictional force on the box, "resisting" the motion of the box. This force is due to the contact between the molecules of the box and the molecules of the floor, and it is always directed against the direction of motion of the object (so, if the object is moving forward, friction acts backwards).
The magnitude of the friction force is given by:
where 
is the coefficient friction, which is a number that depends on the materials of the two surfaces, and N is the normal reaction.
<u>Answers</u>
same distance from the mirror as the object
same size
lateral inversion
<u>Explanation</u>
The image formed by a plane mirror is formed at equal distance from the mirror as the object is.
The size of the image is the same as the size of the object.
The image is laterally inverted. This means that, when a person lifts his right hand, his or her image will raise it's left hand.
The power output is 6500 J - ( 12% of 6500 J)
= 5460 J .
Is the first question complete? Because the work done by the river would be equal to work done by the axle of the wheel.
Explanation:
1.) Work = Force*Distance
2.) The direction of motion lies in the same direction as the tension in the cable. So the work done by tension would be positive.
3.) The direction of the weight (due to gravity) would act opposite to the direction of motion of the elevator, so work done by gravity becomes negative.
