Answer:
(a) 1462.38 m/s
(b) 2068.13 m/s
Explanation:
(a)
The Kinetic energy of the atom can be given as:
K.E = (3/2)KT
where,
K = Boltzman's Constant = 1.38 x 10⁻²³ J/k
K.E = Kinetic Energy of atoms = 343 K
T = absolute temperature of atoms
The K.E is also given as:
K.E = (1/2)mv²
Comparing both equations:
(1/2)mv² = (3/2)KT
v² = 3KT/m
v = √[3KT/m]
where,
m = mass of Helium = (4 A.M.U)(1.66 X 10⁻²⁷ kg/ A.M.U) = 6.64 x 10⁻²⁷ kg
v = RMS Speed of Helium Atoms = ?
Therefore,
v = √[(3)(1.38 x 10⁻²³ J/K)(343 K)/(6.64 x 10⁻²⁷ kg)]
<u>v = 1462.38 m/s</u>
(b)
For double temperature:
T = 2 x 343 K = 686 K
all other data remains same:
v = √[(3)(1.38 x 10⁻²³ J/K)(686 K)/(6.64 x 10⁻²⁷ kg)]
<u>v = 2068.13 m/s</u>
Answer:
There are several reasons for the extinction of species. Some of these can include climate change, natural disasters, environmental destruction, or over-hunting. All of these factors can contribute to the deaths of various animals which ultimately leads to extinction if left unchecked.
Explanation:
The outer surface of the glass expands faster than the inside surface since glass is a fairly good thermal insulator. The outer surface tries to expand without the inner surface doing so at the same time. This is the secret of Pyrex glass. It is more conductive to heat and the inner and outer surface expand (and contract) at the same time.
Answer:
True
Explanation:
Magnetic field lines outside of a permanent magnet always run from the north magnetic pole to the south magnetic pole. Therefore, the magnetic field lines of the earth run from the southern geographic hemisphere towards the northern geographic hemisphere.
Answer:
a) 919 m
b) 183.8 m
Explanation:
140 calories = 140 * 4186 J/calorie = 586040 J
a)When the hiker climbs a mountain, this energy is converted to potential energy, which has the following formula

where m = 65 kg is the mass, g = 9.81 m/s2 is the gravitational acceleration and h is the height that he climbs


b) If only 20% of food energy goes into mechanical energy, then the actual potential energy is
586040 * 0.2 = 117208
Similarly, the height that he could climbs is
