Using F = ma

Question 1

what is the resultant force of an object acted on by two unequal forces acting in opposite direction?

Answer 1

F₁ - F₂ = ma

Question 2

How is tension calculated?

Answer 2

F - T = ma

Question 3

How is rocket thrust calculated?

Answer 3

mg = ma

Question 4

In a lift, when is the tension in the cable less than weight?

Answer 4

moving up and decellerating

moving down and accellerating

Question 5

How is the force of an object moving down a slope calculated?

Answer 5

mg sinθ - Fo = ma

Fo = friction

Question 6

How can force of an engine be added to the force of an object moving down a slope?

Answer 6

F_E + mg sinθ - Fo

Fo is the combined sum of air resistance and breaking force

Question 7

Why does the horziontal forwards force has to change on a vehicle to maintain constant acceleration?

Answer 7

• forward force has to increase
• as drag increases with speed
• so resultant force to remain the same
• otherwise it would decrease