2.2: Skydiver v-t graph

What does a rising or falling line on a velocity-time graph indicate?

• The velocity is constant

• The velocity is changing

• The forces acting are balanced

• The forces acting are unbalanced

What does a horizontal line on a velocity-time graph indicate?

• The velocity is constant

• The velocity is changing

• The forces acting are balanced

• The forces acting are unbalanced

What causes air resistance or drag?

• Friction between the moving body and air molecules

• Friction between the moving body and the ground

• Friction between the moving body and water molecules

• Friction between the moving body and solid objects

Why does drag increase with speed?

• Air molecules gain kinetic energy

• Air molecules lose kinetic energy

• Air molecules remain unaffected

• Air molecules gain potential energy

What happens to the number of collisions with air molecules as an object moves faster?

• The number of collisions decreases

• The number of collisions remains constant

• The number of collisions increases

• The number of collisions becomes zero