Answer:
As the marble starts rolling down the roller coaster, the amount of potential energy stored in the marble decreases while its kinetic energy increases. Potential energy is also converted into heat energy due to friction.
Explanation:
As the marble rolls down the hill its potential energy is converted to kinetic energy (its height decreases, but its velocity increases). When the marble goes back up the loop its height increases again and its velocity decreases, changing kinetic energy into potential energy.
Answer: 11369.46 m/s
Explanation:
We have the following data:
is the mass of the bowling ball
is the velocity of the bowling ball
is the mass of the ping-pong ball
is the velocity of the ping-pong ball
Now, the momentum
of the bowling ball is:
(1)
(2)
And the momentum
of the ping-pong ball is:
(3)
If the momentum of the bowling ball is equal to the momentum of the ping-pong ball:
(4)
(5)
Isolating
:
(6)
(7)
Finally:

Sound level at distance of 15 m is given as 20 dB
so intensity at this distance is given as



now if we move closer to some some distance the sound level is now 50 dB
now the intensity is given as



now we know that



so now the distance from friend must be 47 cm
Answer:
1.36 x 10^-3 cm
Explanation:
Area = 50 ft^2 = 46451.5 cm^2
mass = 6 oz = 170.097 g
density = 2.70 g/cm^3
Let t be the thickness of foil in cm.
mass = volume x density
mass = area x thickness x density
170.097 = 46451.5 x t x 2.70
t = 1.36 x 10^-3 cm
Thus, the thickness of aluminium foil is 1.36 x 10^-3 cm.