Force diagrams and resultant forces

What is the name of the force from the water in this picture?

• Upthrust

• Lift

• Air resistance

• Weight

In an accelerating car, which force is unbalanced?

• Weight

• Thrust

• Normal reaction

• Air resistance

In a free body force diagram, how is the object represented?

• A picture of it

• Arrows

• A dot or box

• However you want

When do you add forces together?

• When they are in the same direction

• When one is up and one is sideways

• When there is more than one

• When they are in opposite directions

What statement is true if an object is accelerating?

• There is no air resistance

• It has thrust

• Forces are unbalanced

• Friction is useful in this case

What is the size and direction of the normal reaction

force which would balance a 50N dog?

• 5 kg upwards

• 50 N upwards

• 50 N downwards

• It is already balanced

For a boat to float, the upthrust and the weight must ________

• be the same size in opposite directions

• both be upwards

• be identical

• add up to cause it to float