Answer:
ω₁ = 8 rad/s
Explanation:
Assuming
1) the clay sticks to the disc we can apply conservation of angular momentum
2) That the disc moment of inertia is 1.5 kg•m²
Initial angular momentum = L = I₀ω₀ = 1.5(14) = 21 kg•m²/s
After the clay joins the party, the moment of inertia is
I₁ = 1.5 + 0.5(1.5²) = 2.625 kg•m²
21 = 2.625ω₁
ω₁ = 8 rad/s
There are 10⁹ picoseconds in 1 Ms
1 picosecond= 10¹² s
1 Ms = 10⁻³ s
so the number of picoseconds in one Ms=(10⁻³ s/1 Ms) * (10¹² Ps/ 1 s)=10⁹
Thus there are 10⁹ picoseconds in 1 Ms
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.
Explanation:
avg spd = total distance/total time
=80/8=10m/s
