Resultant Forces Flashcards

All 5 cards in this deck

What is a resultant force?

The single force that has the same effect as all the original forces acting on the object together.

What are the steps to find the resultant of two forces acting in a straight line?
e.g. 8 N to the right and 3 N to the left

1. Choose a positive direction (take right as positive).
2. Forces in the same direction add, forces in opposite directions subtract: $8 - 3 = 5$.
3. State the size and direction: 5 N to the right.

True or false? When two forces act on an object in opposite directions, you add them to get the resultant.

False. You subtract them, and the resultant acts in the direction of the larger force.

Why must a resultant force be given with a direction as well as a size?

Because force is a vector quantity.

(Higher tier) What are the steps to find the resultant of two forces at right angles using a scale vector diagram?
e.g. 4 N to the right and 3 N upwards

1. Choose a scale and draw the two forces tip-to-tail: 4 cm right, then 3 cm up.
2. Draw the resultant arrow from the start to the finish point.
3. Measure it and use the scale: resultant = 5 N at about $37°$ above the horizontal.