Lesson 11 4.4

• Natuurkunde / Scheikunde
• Middelbare school
• havo, vwo
• Leerjaar 2

This lesson

• rearranging the formula for acceleration
• speed-time graphs
  
• 
  

Learning goals 4.4

• Rearrange the formula for acceleration
  
• Read a speed-time graph correctly
  
• Explain terminal velocity
  

Exercise

• Write down the formula for speed.
  
• What is the unit of speed?

• Write down the formula for accelration
  
• what is the unit of acceleration? Explain
  

v=​t​​d​​

Speed=​time​​distance​​

v: velocity 

d: distance

t: time

Unit of Speed

distance/time

m/s

m/s

a=​t​​v​f​​−v​i​​​​

acceleration=​time​​finalspeed−startingspeed​​

Unit of Acceleration

• speed/time
  
• (m/s)/s
  

m/s

2

Exercise

Rearrange the formula for acceleration to calculate:

• vf
  
• vi
  
• t
  

a=​t​​v​f​​−v​i​​​​

• A car accelerates at a rate of 13m/s2 for 6 seconds, it reaches a speed of 128 km/h. Calculate its initial speed.
  

• A rocket launching  accelerates from rest a rate of 1.5 km/s2 for 8 seconds. Calculate the speed it reaches.

• A cyclist in the decelerates from 22 m/s to a speed of 37 m/s at a rate of 7,5 m/s2. Calculate the time this took.
  

Discussing the homework

•  Worksheet 4.4
• Workbook exercises 4.4

Speed-time graphs

Speed-time graphs

Speed-time graphs

The area under the graph

Calculate the distance traveled in this journey

Terminal velocity

Learning goals 4.4

• Rearrange the formula for acceleration
  
• Read a speed-time graph correctly
  
• Explain terminal velocity