What is the weight of a 19kg stone?

[soulja101]

Homework Statement

a)What is the weight of a 19kg stone?
b)what force if required to raise the stone without acceleration.

Homework Equations

weight=mg
Fnet=ma

The Attempt at a Solution

A)9.8N/kg*19kg
=186kg
B)didnt get how to this part

 

[Kurdt]

Part a) is correct apart from the units.

Part b) what do you know of Newton's laws? I think you have to neglect the initial acceleration and consider the stone being raised at a constant speed.

 

[soulja101]

is the answer to Part B gravity

 

[Kurdt]

Whats Newton's first law?

 

[soulja101]

is it inertia

 

[Kurdt]

Newton's first law states that an object will remain stationary or at uniform velocity if no net force acts upon it.

 

[soulja101]

so for part B the answer is that the net force must raise it

 

[Kurdt]

Yes in a manner. But its a little more complicated.

 

[soulja101]

do i have to do any calculations for the anser

 

[hover]

The Attempt at a Solution

A)9.8N/kg*19kg
=186kg
B)didnt get how to this part

Not to be picky but grams and kilograms are not a measurment of weight, they are a measurment of mass. Also Newtons second law is F=ma. 19kilograms is right but if I'm correct you should have 9.8m/s not N/kg. Lastly 9.8m/s*19kg would equal 186 Newtons, or just about 41 pounds.

hope i helped