Physics Grade 7 - March Test Review

What does a distance-time graph show?

• Distance (距离) and speed (速度)

• Distance (距离) and time (时间)

• Time (时间) and direction (方向)

• Speed (速度) and direction (方向)

What happens to the line in a distance-time graph if an object is not moving?

• It goes up

• It goes down

• It is flat (平的)

• It is curved (弯曲的)

A steeper slope (斜率) on a distance-time graph means:

• A) Slow speed (慢速)

• B) No speed (没有速度)

• C) Fast speed (快速)

• D) Constant speed (恒定速度)

When the line on a distance-time graph is curved (弯曲的), it indicates:

• Constant speed (恒定速度)

• No motion (没有运动)

• Changing speed (变化的速度)

• Backward motion (向后运动)

The area under the line on a distance-time graph represents:

• Speed (速度)

• Distance (距离)

• Time (时间)

• Direction (方向)

What are balanced forces (平衡力)?

• Forces that are equal and opposite (相等且相反的力)

• Forces that cause motion (运动)

• Forces that change direction (方向)  

• Forces that increase speed (速度)
  
  

What happens when unbalanced forces (不平衡力) act on an object?

• The object stays still (静止)

• The object moves (移动)

• The object changes shape (形状)

• The object makes noise (噪音)

A parked car has: A) Unbalanced forces (不平衡力) B) Balanced forces (平衡力) C) No forces (没有力) D) Only friction (摩擦)

• Unbalanced forces (不平衡力)

• Balanced forces (平衡力)

• No forces (没有力)

• Only friction (摩擦)

Which of the following is an example of unbalanced forces?

• Two people pushing a box equally (均匀)

• A child pulling a toy (玩具)

• A book resting on a table (桌子)

• A balloon floating (漂浮)

What do you feel when you push a heavy object?

• Only balanced forces (平衡力)

• Only unbalanced forces (不平衡力)

• Both balanced and unbalanced forces

• No forces (没有力)