Positive And Negative Work

Explanation
The given answer "positive, Positive" suggests that the student is exerting a force in the upward direction to lift the box to a high shelf. This indicates that the force applied by the student is in the same direction as the displacement of the box, resulting in positive work being done. The repetition of "positive" emphasizes the direction of both the force and the work as being upward.

Explanation
The term "negative" is used twice in the answer to indicate that the student is exerting a downward force on the box, which is opposite to the direction of the force of gravity. This downward force is required to lower the box to the ground. The repetition of the word "negative" emphasizes that the force exerted by the student is in the opposite direction of the force of gravity.

Explanation
When a student lowers and then lifts a box back to its original height, no work is done. This is because work is defined as the transfer of energy that occurs when a force is applied to an object and the object is displaced in the direction of the force. In this case, although the student applies a force to the box, the box ends up at the same height as before, so no displacement occurs. Therefore, no work is done on the box.

Explanation
The student throwing a shot put is a positive action because it involves physical activity and participation in sports. It shows that the student is engaged in a healthy and active lifestyle, which is beneficial for their physical well-being. Additionally, participating in sports can also have positive effects on mental and emotional health, as it provides opportunities for social interaction, teamwork, and personal growth. Overall, the act of throwing a shot put demonstrates a positive attitude towards fitness and sportsmanship.

Explanation
When a student pulls back on an arrow in a bow, they are exerting a force in the opposite direction of the arrow's initial motion. This force is known as a tension force and it acts towards the student, which is considered as the positive direction. Therefore, the answer is positive.

Explanation
When the answer is stated as "positive" in the context of a student pushing a crate up an incline, it implies that the force exerted by the student is in the same direction as the displacement of the crate. In other words, the student is applying a force that helps the crate move up the incline. This is a positive work situation because the force and displacement are in the same direction, resulting in positive work being done on the crate.