陳皮梅 asked in 科學其他:科學 · 1 decade ago

兩題用英文寫成的物理題觀念題

請問下列選項何者正確

You are pushing a wooden crate across the floor at constant speed. You decide to turn the crate on end,

reducing by half the surface area in contact with the floor. In the new orientation, to push the same crate

across the same floor with the same speed, the force that you apply must be about

1. four times as great

2. twice as great

3. equally great

4. half as great

5. one-fourth as great

as the force required before you changed the crate’s orientation.

這題我猜是3

You are a passenger in a car and not wearing your seat belt. Without increasing or decreasing its

speed, the car makes a sharp left turn, and you find yourself colliding with the right-hand door. Which is

the correct analysis of the situation?

1. Before and after the collision, there is a rightward force pushing you into the door.

2. Starting at the time of collision, the door exerts a leftward force on you.

3. both of the above

4. neither of the above

這題我猜3

1 Answer

Rating
  • LI
    Lv 7
    1 decade ago
    Favorite Answer

    Q1:3

    摩擦力與接觸面積無關。

    Q2:2

    你的身體因慣性而有保持直線前進的趨勢,而車子突然左轉,其實是向左移動的車窗,撞向不偏左右的你。

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