科学

什么是力？

What is the meaning of force?

• 拉力施加在物体上

  The pulling effect of an object

• 推力施加在物体上

  The pushing effect of an object

• 推力和拉里施加在物体上

  The pulling and pushing effect of an object

• 物体的移动而产生一种力量

哪项显示活动涉及推力？

Which of the following activities involves a pushing force?

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上图显示一个男人正在进行活动。

Diagram above shows a man carrying out an activity.

什么力涉及这个活动？

What is the force involved in this activity?

• 推力 Pulling force

• 拉力 Pushing force

• 地心引力 Gravity force

• 压缩力 Compressing force

哪项的活动涉及拉力和推力？

Which of the following activities involves pushing and pulling forces?

• 打排球 Playing volleyball

• 放风筝 Flying a kite

• 推轮椅 Pushing a wheelchair

• 为自行车的轮胎填气 Pumping bicycle tyres

上图显示 球员在踢球。

Diagram above shows a player is kicking a ball.

当球被踢后， 球涉及什么力使球移动？、

What makes the ball move after being kicked?

• 脚力 Leg force

• 推力 Pushing force

• 拉力 Pulling force

• 摩擦力 Frictional force

下列哪项活动涉及力能改变物体的形状？

Which of the following actions of force causes a change in shape?

• 在操场骑自行车 Cycling in the field

• 球在地板上滚动 Rolling a ball on the floor

• 划船 Rowing a boat

• 吹气球 Blowing a balloon

如果一件物体涉及力，物体将是什么情况？

What will happen if an object is acted on by a force?

• 物体的质量将会增加 The object will become heavier

• 物体的质量将会减少 The object will become lighter

• 物体的速度将会减少 The object will move slowly

• 物体 的颜色会改变 The object will change colour

下列哪项活动显示力能改变物体的形状？

Which of the following shows that a force can change the shape of an object?

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上图显示球在移动。

Diagram above shows that a ball is moving.

如果球员从相反的方向踢那个球， 球将是什么情况？

What will happen if a player kicks the ball form the opposite direction?

• 球j将会静止 The ball will stop

• 球将会改变形状 The ball will change its shape

• 球将会慢慢地移动 The ball will move slowly

• 球将会改变移动的方向

  The ball will change its direction of movement

什么是摩擦力？

What is the meant by frictional force?

• 一种力涉及阻碍物体的移动

  An effort to resist movement

• 一种力涉及改变物体

  A force to change an object

• 一种力涉及当两个物体的表面互相接触时所产生的阻碍物体移动

  The force produced when two surfaces are in contact with each other

• 推力和拉力施加在物体上

  Pulling and pushing that is applied on an object