Answer:
The speed of the car at the apex of the loop must be grater than 2.45 m/s
Explanation:
In order for the car to not fall off the track at the apex of the loop, the norm force of the track at the apex must be greater than zero.
Assuming frictionless life on the track which is also to have a perfectly circular shape near the top (radius being 0.25m), the norm force of the track and gravity both point down and result in the centripetal force:

The formula for centripetal force on a circular trajectory is

and so the condition for the car to stay on the track can be written as

The speed of the car at the apex of the loop must be grater than 2.45 m/s
Answer:
630.75 j
Explanation:
from the question we have the following
total mass (m) = 54.5 kg
initial speed (Vi) = 1.4 m/s
final speed (Vf) = 6.6 m/s
frictional force (FF) = 41 N
height of slope (h) = 2.1 m
length of slope (d) = 12.4 m
acceleration due to gravity (g) = 9.8 m/s^2
work done (wd) = ?
- we can calculate the work done by the boy in pushing the chair using the law of law of conservation of energy
wd + mgh = (0.5 mVf^2) - (0.5 mVi^2) + (FF x d)
wd = (0.5 mVf^2) - (0.5 mVi^2) + (FF x d) - (mgh)
where wd = work done
m = mass
h = height
g = acceleration due to gravity
FF = frictional force
d = distance
Vf and Vi = final and initial velocity
wd = (0.5 x 54.5 x 6.9^2) - (0.5 x 54.5 x 1.4^2) + (41 x 12.4) - (54.5 X 9.8 X 2.1)
wd = 630.75 j
Sound waves in air (and any fluid medium) are longitudinal waves because particles of the medium through which the sound is transported vibrate parallel to the direction that the sound wave moves.
Answer:
The average speed of molecule of oxygen is one-fourth of the speed of the hydrogen molecule.
Explanation:
The kinetic energy of gas molecule is given by following equation:

Since the temperature (T) is constant for both molecules. Therefore, there kinetic energies will also be the same. Therefore,

<u>The average speed of molecule of oxygen is one-fourth of the speed of the hydrogen molecule.</u>