Y2_T4_REVIEW§4.1-§4.3

• Science
• Middelbare school
• havo, vwo
• Leerjaar 2

HW CHECK

§4.1 

§4.2

§4.3

FORCES WORKSHEET

§4.1 - Learning Goals:

• I can explain what a force is and can identify different types of forces.
• I can calculate the gravitational force acting on an object.
• I can draw arrows on a force diagram with the correct point of application, magnitude and direction.
• I can calculate the resultant force of forces going in the same direction or opposite directions of each other.  
• VWO ONLY - I can calculate the resultant force of two perpendicular forces 

P.154-157

§4.1 - Keywords:

• Gravity 
• Applied force 
• Air resistance 
• Friction 
• Tension force 
• Spring force 
• Normal force
• Resultant force 
• Point of application
• Direction
• Magnitude

P.154-157

F​g​​

F​a​​

F​air​​

F​f​​

F​t​​

F​s​​

F​n​​

F​res​​

How does air resistance affect the motion of a skydiver as they fall towards the ground?

1. Air resistance decreases a skydivers rate of falling.
2. Air resistance decreases a skydivers rate of acceleration.
3. Air resistance increases a skydivers rate of acceleration.
4. Air resistance stops a skydivers from falling.

What is the force of gravity on a 50 kg object on Earth's surface, where the force due to gravity is approximately 9.81 N/kg?

If a person has a mass of 70 kg and is standing on the surface of the moon, where the force due to gravity is approximately 1.62 N/kg, what is the force of gravity acting on them?

Two forces of 5 N (left) and 8 N (right) are acting on an object in opposite directions. What is the magnitude and direction of the resultant force acting on the object?

§4.2 - Learning Goals:

• I can describe the concept of speed and understand which measurements and units are necessary to calculate it.
• I can calculate the speed (or distance or time) of an object using the speed formula.
• I can convert speed between the units of m/s and km/h.   
• I can create and interpret s,t-diagrams relating to an object’s motion. 

P.162-165

§4.2 - Keywords:

• Speed
• s,t-diagram

P.162-165

A car travels a distance of 240 km in 4 hours. What is the average speed of the car in kilometers per hour (km/h)?

A train covers a distance of 400 meters in 20 seconds. What is the speed of the train in kilometers per hour (km/h)?

A car travels at a speed of 60 km/h. How many minutes will it take to travel a distance of 18 km?

A train travels at a speed of 80 km/h. How far will it travel in 100 minutes?

§4.3 - Learning Goals:

• I can describe the concept of acceleration and understand which measurements and units are necessary to calculate it.
• I can calculate the acceleration of an object using the acceleration formula.
• I can create and interpret v,t-diagrams relating to an object’s change in motion.
• I can use an object’s resultant force to determine what type of motion it has.

P.172-175

§4.3 - Keywords:

• Acceleration
• Deceleration
• v,t-diagram

P.172-175

A car traveling at 60 km/h suddenly hits the brakes and comes to a complete stop in 5 seconds. What is the car's acceleration?

A rock is thrown off a cliff with an initial velocity of 30 m/s. After 5 seconds it has a velocity of 79 m/s, what is its acceleration during the fall?

A car is traveling along a straight road with a constant speed of 30 m/s. If the engine provides a driving force of 5000 N, and air resistance provides a drag force of 2000 N in the opposite direction, what is the resultant force acting on the car? Calculate and explain what other force is acting on the car.

A cyclist is pedaling a bicycle on a flat road with a constant applied force of 200 N. The bicycle experiences resistive forces of 250 N. What is the resultant force acting on the bicycle? Is the cyclist accelerating, decelerating, or moving at a constant speed?

Study for the quiz:

• study all the glossaries
• study the notes
• review all the hw exercises 

Make sure you bring:

• ruler/triangle
• calculator
• pen
• highlight marker