2020 RSHS Year 7 Physics Summative

If an object starts to accelerate:

• A balanced force must be acting on it

• An unbalanced force must be acting on it

• Gravity must be acting on it

• Speed must be acting on it

When forces are balanced, the net force is :

• greater than the sum of the forces

• zero

• less than the sum of the forces

• equal to the largest force

A soccer ball takes 20s to roll 10m. What is the average speed of the ball?

• 200 m/s

• 2 m/s

• 5 m/s

• 0.5 m/s

Which describes how speed changes with time?

• Acceleration

• Average speed

• Gravity

• Inertia

Which one of the following statements is true about friction?

• Friction has very little effect on the direction of motion of an object.

• Friction acts in the opposite direction of the normal force.

• The amount of pressure between two surfaces is the only factor that determines frictional force.

• Frictional force always opposes motion or attempted motion.

Newtons First Law is also known as the law of:

• Acceleration

• Average speed
  
  

• Gravity

• Inertia

If acceleration due to gravity on Earth is rounded to 10m/s² an the object has a weight of 475N, what is the object’s mass in kg?

• 4.75 kg

• 47.5 kg

• 475 kg

• 4750 kg

A vase of flowers is stationary on a table. Which one of the statements best explains why the vase is stationary?

• There are no forces on the vase.

• The force of gravity pulls the vase downwards.

• All forces acting on the vase are in balance.

• Gravity pulling down on the vase and the force of the table pushing up on the vase are equal.

The apparatus used for measuring force is called a

• Pendulum

• Ruler

• Spring balance

• Thermometer

A student investigated the relationship between the weight of a block and the friction between it and the surface.

As he added weights to the block, he found that the force needed to move the block

• decreases

• increases

• stays the same