Lesson 10 – calculations

• Natuurkunde / Scheikunde
• Middelbare school
• havo, vwo
• Leerjaar 1

1.4 Gravity

This lesson

• Check exercise E
  
• Rearranging the formula for weight
  
• A procedure for doing calculations
  
• Worksheet – calculations weight
  

Learning goals

• To apply the formula for weight in calculations.
  

• Be able to rearrange the forumla for weight and apply this in calculations.
  

• Learn a procedure for doing calculations.
  

Exercise E

Exercise E

Mass on earth	Weight on Earth (N)	Mass on moon	Weight on the moon (N)	Mass on planet	weight on planet (N)
500 g					25
2 kg					100

Exercise E

Mass on earth	Weight on Earth (N)	Mass on moon	Weight on the moon (N)	Mass on planet	weight on planet (N)
500 g	5	500 g	0.8	500 g	25
2 kg					100

Exercise E

Mass on earth	Weight on Earth (N)	Mass on moon	Weight on the moon (N)	Mass on planet	weight on planet (N)
500 g	5	500 g	0.8	500 g	25
2 kg	20	2 kg	3.2	2 kg	100

Exercise E

Mass on earth	Weight on Earth (N)	Mass on moon	Weight on the moon (N)	Mass on planet	weight on planet (N)
50 g	0.5	50 g	0.08	50 g	2.5
500 g	5	500 g	0.8	500 g	25
2 kg	20	2 kg	3.2	2 kg	100
25 kg	250	25 kg	40	25 kg	1250

Exercise E

How do we calculate the gravitational field strength of the unknown planet?

Mass on earth	Weight on Earth (N)	Mass on moon	Weight on the moon (N)	Mass on planet	weight on planet (N)
2 kg	20	2 kg	3.2	2 kg	100

Rearranging the formula for weight

w=m⋅g

6=3⋅2

A procedure for doing calculations

1. Given
   
2. Asked
   
3. Formula
   
4. Calculation
   
5. Answer
   

Exercise

Procedure

1. Given
   
2. Asked
   
3. Formula
   
4. Calculation
   
5. Answer
   

A man has a weight of 813.4 N on earth. The gravitational field strength on earth is 

9.8 N/kg. Calculate his mass.

Exercise

Procedure

1. Given
   
2. Asked
   
3. Formula
   
4. Calculation
   
5. Answer
   

A giraffe has a weight of 19521.6 Newton on Earth. The gravitational field of earth is 9.8 N/kg. Calculate the mass of this Giraffe.

Worksheet mass, weight and gravitational field strength

This is the homework for next lesson

Learning goals

• Be able to rearrange the forumla for weight and apply this in calculations.
  

• Learn a procedure for doing calculations.
  

Homework

The worksheet about mass, weight and gravitational field strength