17.7. Conclusions

Try these first

1. 1.

   Define drag in your own words.

   Hint

   Think about the force acting against a moving object.

2. 2.

   What is lift?

   Hint

   Consider how planes achieve flight.

3. 3.

   What is drag?

   • A force acting in the direction of motion
   • A force opposing the motion
   • A type of potential energy

   Hint

   Think about how water affects a boat moving through it.

4. 4.

   True or False: Lift is caused by pressure differences on opposite surfaces.

   • True
   • False

   Hint

   Consider airplane wings as an example.

5. 5.

   An airplane hovering at a steady height experiences a drag force of 100 N and a lift force of 150 N. Discuss how the airplane can achieve stability.

   Hint

   Consider what happens if lift suddenly decreases.

6. 6.

   Calculate the terminal velocity for a spherical object with a diameter of 0.1 m, mass of 0.2 kg in water with density 1000 kg/m³.

   Hint

   Remember that terminal velocity occurs when the net force is zero.