The kinetic energy K given to the helium nucleus is equal to its potential energy, which is
![E=q \Delta V](https://tex.z-dn.net/?f=E%3Dq%20%5CDelta%20V)
where q=2e is the charge of the helium nucleus, and
![\Delta V](https://tex.z-dn.net/?f=%5CDelta%20V)
is the potential difference applied to it.
Since we know the kinetic energy, we have
![E=K=85~keV=q \Delta V](https://tex.z-dn.net/?f=E%3DK%3D85~keV%3Dq%20%5CDelta%20V)
and from this we can find the potential difference:
Solution:
initial sphere mvr = final sphere mvr + Iω
where I = mL²/3 = 2.3g * (2m)² / 3 = 3.07 kg·m²
0.25kg * (12.5 + 9.5)m/s * (4/5)2m = 3.07 kg·m² * ω
where: ω = 2.87 rad/s
So for the rod, initial E = KE = ½Iω² = ½ * 3.07kg·m² * (2.87rad/s)²
E = 12.64 J becomes PE = mgh, so
12.64 J = 2.3 kg * 9.8m/s² * h
h = 0.29 m
h = L(1 - cosΘ) → where here L is the distance to the CM
0.03m = 1m(1 - cosΘ) = 1m - 1m*cosΘ
Θ = arccos((1-0.29)/1) = 44.77 º
First we have to calculate the volume of the living room:
V = L x W x H = 4.5 m * 3.4 m * 2.9 m
V = 44.37 m³
We know that Density = 1.29 kg/m²
D = m / V
m = D · V
m = 1.29 kg/m³ · 44.37 m³
m = 57.2373 kg ≈ 57.2 kg
Answer: The approximate mass of air in living room is 57.2 kg.
Answer:
a) 25.5°(south of east)
b) 119 s
c) 238 m
Explanation:
solution:
we have river speed
=2 m/s
velocity of motorboat relative to water is
=4.2 m/s
so speed will be:
a)
=
+![v_{m/r}](https://tex.z-dn.net/?f=v_%7Bm%2Fr%7D)
solving graphically
![v_{m}=\sqrt{v^2_{r}+v^2_{m/r}}](https://tex.z-dn.net/?f=v_%7Bm%7D%3D%5Csqrt%7Bv%5E2_%7Br%7D%2Bv%5E2_%7Bm%2Fr%7D%7D)
=4.7 m/s
Ф=![tan^{-1} (\frac{v_{r}}{v_{m/r}} )](https://tex.z-dn.net/?f=tan%5E%7B-1%7D%20%28%5Cfrac%7Bv_%7Br%7D%7D%7Bv_%7Bm%2Fr%7D%7D%20%29)
=25.5°(south of east)
b) time to cross the river: t=
=
=119 s
c) d=
=(2)(119)=238 m
note :
pic is attached
Answer:
The radius of strontium atom is
2.14 E-8cm
Explanation:
Go through the attached file for a comprehensive detailed explanation.