Answer:
A. The horizontal velocity vector points to the right & equals v cos θ.
Explanation:
The motion describes a parabolic path, where the horizontal speed is constant and the horizontal velocity vector always points to the right and equals v*cos θ.
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
Explanation:
The free fall acceleration is:
F = ma
20 N = (0.50 kg) a
a = 40 m/s²
The mass of Planet X is:
F = GMm / r²
20 N = (6.67×10⁻¹¹ Nm²/kg²) M (0.50 kg) / (4.0×10⁶ m)²
M = 9.6×10²⁴ kg
Answer:
Work done will be 78.76 J
Explanation:
We have given initial volume of the gas 
Pressure is given by 
Final volume 
Change in volume 
We know that work done is given by
Work done will be 78.76 J
Answer: Friction stops things from sliding apart. If there was no friction everything would slide to the lowest point. With no friction the only possible movement would be falling to a lower point under gravity.
Explanation: In a frictionless world, more objects would be sliding about, clothes and shoes would be difficult to keep on and it would be very difficult for people or cars to get moving or change direction. Students should be encouraged to consider how dependant their world is on the beneficial action of friction. Humans and other objects will become weightless without gravity. If we have no gravity force, the atmosphere would disappear into space, the moon would collide with the earth, the earth would stop rotating, we would all feel weightless, the earth would collide with the sun, and as a consequence.
