Answer
D. The average speed is 2.5 meters/second, and the average velocity is 0 meters/second.
The difference between speed and velocity is that, speed is a scalar quantity while velocity is a vector quantity.
Average speed = total distance/Total time
= (150 + 150) / (2×60)
= 300/120
= 2.5 m/s
Average velocity = Total displacement/ Total time
= (150 + -150) / (2 × 60)
= 0/120
= 0 m/s
The weight of anything is (mass) x (gravity in the place where the thing is).
Gravity on Earth is about 9.8 newtons per kilogram, so on Earth,
the weight of the book is
(2.06 kg) x (9.8 N/kg) = <em>20.19 newtons</em> .
Another way to get around it is:
On Earth, 1 kg of mass weighs about 2.205 pounds, so on earth,
the weight of the book is
(2.06 kg) x (2.205 pounds/kg) = <em>4.54 pounds </em>.
use the formula: v^2=(3kT)/m
Where:
<em>v is the velocity of a molecule</em>
<em>k is the Boltzmann constant (1.38064852e-23 J/K)</em>
<em>T is the temperature of the molecule in the air</em>
<em>m is the mass of the molecule</em>
For an H2 molecule at 20.0°C (293 K):
v^2 = 3 × 1.38e-23 J/K × 293 K / (2.00 u × 1.66e-27 kg/u)
v^2 = 3.65e+6 m^2/s^2
v = 1.91e+3 m/s
For an O2 molecule at same temp.:
v^2 = 3 × 1.38e-23 J/K × 293 K / (32.00 u × 1.66e-27 kg/u)
v^2 = 2.28e+5 m^2/s^2
v = 478 m/s
Therefore, the ratio of H2:O2 velocities is:
1.91e+3 / 478 = 4.00
B) initial speed (u)=3
final speed (v)=8
time (t)= 10
acceleration (a)=?
v=u+at
8=3+a(10)
5=10a
a=1/2= 0.5 m/s²
c)displacement (s)=?
1st section of journey
v ²=u ²+2as
8 ²=3 ²+2(0.5)s
64=9+1s
s=55meters
2nd section of journey
a=0
t=7
u=8
s=?
s=ut+1/2at²
s=8(7)+1/2(0)(7 ²)
s=56 meters
56+55= 111 meters
(For graph x axis =time (sec) & y axis= velocity (m/s))
Answer:
a) 2.02 years
b) 8.1 x 10⁻⁸.
Explanation:
Time period of a rotating body T² is proportional to radius of orbit R³ So
T₁² / T₂² = R₁³ /R₂³ ( T₁ and R₁ is time period and radius of orbit of the earth .)
1² / T₂² =( 1/1.6)³
T₂ = 2.02 years.
Kinetic energy of an orbiting body = 1/2 m v₀² ( v₀ is orbital speed)
= 1/2 m x 2 g R = m x G m/R² X R= m² x G /R
Kinetic energy of asteroid K₁ / kinetic energy of earth K₂ =
(mass of asteroid/mass of earth)² x( radius of earth / radius of asteroid)
=( 3.6 x 10⁻⁴)² x 1/1.6 = 8.1 x 10⁻⁸ .
