I need homework help

1. A physical scicence test book has a mass of 2.2 kg What is the weight on the earth?

2. Whar is the weight on Mars (g = 3.7 m/s2)

3. If the textbook weighs 19.6 newtons on Venus, what is the strength of gravity on venus?

4. Of all the planets in our solar system, Jupiter has the greatest gravitational strenght. If a 0.5 kg pair of running shoes would weigh 11.55 newtons on Jupiter, what is the strengh of gravity there?

5. If he same pair of shoes weighs 0.3 newtons on Pluto, what is the strenght of gravity on pluto?

6. what does the pair of shoes weigh on earth?

Big Big Thanks for any help!!


Sagot :

1) the weight of an object at Earth's surface is given by [tex]F=mg[/tex], where m is the mass of the object and [tex]g=9.81 m/s^2[/tex] is the gravitational acceleration at Earth's surface. The book in this problem has a mass of m=2.2 kg, therefore its weight is 
[tex]F=mg=(2.2 kg)(9.81 m/s^2)=21.6 N[/tex]

2) On Mars, the value of the gravitational acceleration is different:[tex] g=3.7 m/s^2[/tex]. The formula to calculate the weight of the object on Mars is still the same, but we have to use this value of g instead of the one on Earth: [tex]F=mg=(2.2 kg)(3.7 m/s^2)=8.1 N[/tex]

3) The weight of the textbook on Venus is F=19.6 N. We already know its mass (m=2.2 kg), therefore by re-arranging the usual equation F=mg, we can find the value of the gravitational acceleration g on Venus: 
[tex]g= \frac{F}{m}= \frac{ 19.6 N}{2.2 kg}=8.9 m/s^2[/tex]

4) The mass of the pair of running shoes is m=0.5 kg. Their weight is F=11.55 N, therefore we can find the value of the gravitational acceleration g on Jupiter by re-arranging the usual equation F=mg: 
[tex]g= \frac{F}{m} = \frac{11.55 N}{0.5 kg} =23.1 m/s^2[/tex]

5) The weight of the pair of shoes of m=0.5 kg on Pluto is F=0.3 N. As in the previous step, we can calculate the strength of the gravity g on Pluto as 
[tex]g= \frac{F}{m} = \frac{0.3 N}{0.5 kg} =0.6 m/s^2[/tex]

6) On Earth, the gravity acceleration is [tex]g=9.81 m/s^2[/tex]. The mass of the pair of shoes is m=0.5 kg, therefore their weight on Earth is 
[tex]F=mg=(0.5 kg)(9.81 m/s^2)=4.9 N[/tex]