A projectile fired upward from the Earth's surface will usually slow down, come momentarily to rest, and return to Earth. For a certain initial speed, however it will move upward forever, with its speed gradually decreasing to zero just as its distance from Earth approaches infinity. The initial speed for this case is called escape velocity. You can find the escape velocity v for the Earth or any other planet from which a projectile might be launched using conservation of energy. The projectile of mass m leaves the surface of the body of mass M and radius R with a kinetic energy Ki = mv²/2 and potential energy Ui = -GMm/R. When the projectile reaches infinity, it has zero potential energy and zero kinetic energy since we are seeking the minimum speed for escape. Thus Uf = 0 and Kf = 0. And from conservation of energy,
Ki + Ui = Kf + Uf
mv²/2 -GMm/R = 0
∴ v = √(2GM/R)
This is the expression for escape velocity.
Answer:
Explanation:
If Ek is the kinetic energy and m is the mass and v is the velocity then v can be calculated as follows
Ek= 1/2 ×( m × v² )
2Ek= mv²
2Ek/m = v²
v =√(2Ek/m)
m = 0.1 kg
v= √(2x8/0.1)= 12.65 m/s
The correct answer is:
<span>Become positively or negatively charged
In fact, an insulator is a material where charges cannot move freely. Therefore, it can be positively or negatively charge (for example, if it is rubbed against another object, the insulator can remain with an excess of charge), but it cannot transfer charge to other objects.</span>
Answer: car B has travelled 4times as far as Car A
d=vi*t+1/2at^2
No initial velocity so equation becomes;
d=1/2at^2 and the acceleration is the same between both only time is different;
Car A d=1/2a(1)^2
Car B d=1/2a(2)^2
Car A d= 1^2=1
Car B d= 2^2=4
Car B d=4*Car A
So car B has travelled 4 times as far as car A
The volume of every sphere is
Volume = (4/3) (pi) (radius)³
When you say "across", I think you mean the diameter of the ball.
The radius is half of the diameter = 12 inches.
Volume = (4/3) (pi) (12 inches)³
= (4/3) (pi) (1,728 cubic inches)
= 7,238.2 cubic inches . (rounded)
