The first option is true, water vapor helps keep the Earth's heat from escaping into space.
Momentum is one of those things that are 'conserved' (like energy). That means the total amount of momentum in an isolated system is the same after some event as it was before the event.
Before the ear-splitting explosion, while the firecracker and the billiard balls were just sitting there on the frictionless table, the momentum of the system was zero, because nothing was moving. Right there, that tells us that the total momentum of all the balls and the fragments of the firecracker ... if you add up all the momentum vectors AFTER the explosion ... the sum is still zero. (D)
Answer:
- 8.33 x 10⁻³ rad /s ( anticlockwise)
Explanation:
The rotational movement of beetle and turntable is caused by torque generated by internal forces , we can apply conservation of angular momentum.
That is ,
I₁ ω₁ = I₂ω₂ , ω₁ and ω₂ are angular velocity of beetle and turntable respectively.
ω₁ + ω₂ = .05 radian /s ( given )
Momentum of inertia of beetle I₁ = mass x (distance from axis)²
= 15 x 10⁻³ x R² ( R is radius of the turntable )
Momentum of inertia of turntable I₂ =1/2 mass x (distance from axis)²
= 75/2 x 10⁻³ x R² ( R is radius of the turntable )
I₁ ω₁ = I₂ω₂ ,
15 x 10⁻³ x R² x ( .05 - ω₂ ) = 75/2 x 10⁻³ x R² ω₂
15 x ( .05 - ω₂ ) = 75/2 x ω₂
.75 - 15ω₂ = 37.5ω₂
.75 = 52.5 ω₂
ω₂ = - 14.3 x 10⁻³ rad /s ( anticlockwise)
(i)1.5cm
(ii)4.5cm
(iii)10cm
