It's not so much a "contradiction" as an approximation. Newton's law of gravitation is an inverse square law whose range is large. It keeps people on the ground, and it keeps satellites in orbit and that's some thousands of km. The force on someone on the ground - their weight - is probably a lot larger than the centripetal force keeping a satellite in orbit (though I've not actually done a calculation to totally verify this). The distance a falling body - a coin, say - travels is very small, and over such a small distance gravity is assumed/approximated to be constant.
Answer:
Properties of matter
Explanation:
All properties of matter are either extensive or intensive and either physical or chemical. Extensive properties, such as mass and volume, depend on the amount of matter that is being measured. Intensive properties, such as density and color, do not depend on the amount of matter.
The particles that carry charge through wires in a circuit are mobile electrons. The electric field direction within a circuit is by definition the direction that positive test charges are pushed. Thus, these negatively charged electrons move in the direction opposite the electric field.
Expensive: Hydrogen gas actually takes a considerable measure of work to free if from different components. If it were basic and simple to separate, everybody would be utilizing it. It’s now being utilized to power some hybrid vehicles, yet right now it is not a reasonable type of fuel for everybody, mainly because it’s pricey and it’s difficult to get it from place to place. Until research and innovation goes far enough to make this a simpler and cheaper task, hydrogen will likely be something that only the rich can afford.Not Enough Hydrogen Fuel Stations: As you likely know, it’s very difficult to change “the way things are.” As difficult as hydrogen is to create and transport, it gets to be considerably pricier when you consider attempting to utilize it to supplant fuel. There is no current framework set up to hydrogen as the primary fuel for the normal driver. Service stations and vehicles themselves would all must be changed in order to use hydrogen, which can take a lot of time and money to do. It doesn’t seem cost efficient to change from the norm.Safety Concerns: Hydrogen in itself has a lot of power behind it. Though it is less dangerous than gasoline, it’s profoundly flammable and constantly in the news for the potential dangers connected with it. Unlike gas, hydrogen has no smell. Sensors must be used to detect a leak.
Answer:
The velocity of the man is 0.144 m/s
Explanation:
This is a case of conservation of momentum.
The momentum of the moving ball before it was caught must equal the momentum of the man and the ball after he catches the ball.
Mass of ball = 0.65 kg
Mass of the man = 54 kg
Velocity of the ball = 12.1 m/s
Before collision, momentum of the ball = mass x velocity
= 0.65 x 12.1 = 7.865 kg-m/s
After collision the momentum of the man and ball system is
(0.65 + 54)Vf = 54.65Vf
Where Vf is their final common velocity.
Equating the initial and final momentum,
7.865 = 54.65Vf
Vf = 7.865/54.65 = 0.144 m/s
