OK.
But first we need to know . . .
-- Where is Riverdale ?
-- What is the air temperature there right now ?
-- What kind of system is being used now ?
-- Where can we get a complete description of the groundwater system ?
Anytime that an unstable nucleus emits alpha or bets particles, the number of protons and neutrons changes. ... In the fission process, when the nucleus splits, both neutrons and energy are released
Before the launch, the momentum of the (spacecraft + asteroid) was zero. So after the launch, the momentum of the (spacecraft + asteroid) has to be zero.
Momentum = (mass) x (velocity)
Momentum after the launch:
Spacecraft: (1,000 kg) x (250 m/s) = 250,000 kg-m/s
Asteroid: (mass) x (-25 m/s)
Their sum: 250,000 - 25(mass) .
Their sum must be zero, so 250,000 kg-m/s = (25 m/s) x (mass)
Divide each side by 25 : 10,000 kg-m/s = (1 m/s) x (mass)
Divide each side by (1 m/s) : 10,000 kg = mass
The first sentence is a chemical change because it is two component's that when mixed together you make bubbles and the second one is physical because you are making the bubbles cause just setting the straw in there is just doing nothing
Explanation:
They probably put "rolls without slipping" in there to indicate that there is no loss in friction; or that the friction is constant throughout the movement of the disk. So it's more of a contingency part of the explanation of the problem.
(Remember how earlier on in Physics lessons, we see "ignore friction" written into problems; it just removes the "What about [ ]?" question for anyone who might ask.)
In this case, you can't ignore friction because the disk wouldn't roll without it.
As far as friction producing a torque... I would say that friction is a result of the torque in this case. And because the point of contact is, presumably, the ground, the friction is tangential to the disk. Meaning the friction is linear and has no angular component.
(You could probably argue that by Newton's 3rd Law there should be some opposing torque, but I think that's outside of the scope of this problem.)
Hopefully this helps clear up the misunderstanding for you.
