Answer:
(A) -2940 J
(B) 392 J
(C) 212.33 N
Explanation:
mass of bear (m) = 25 kg
height of the pole (h) = 12 m
speed (v) = 5.6 m/s
acceleration due to gravity (g) = 9.8 m/s
(A) change in gravitational potential energy (ΔU) = mg(height at the bottom- height at the top)
height at the bottom = 0
= 25 x 9.8 x (0-12) = -2940 J
(B) kinetic energy of the Bear (KE) = 
= 
= 392 J
(C) average frictional force = 
- change in KE (ΔKE) = initial KE - final KE
- ΔKE = -
- when the Bear reaches the bottom of the pole, the final velocity (Vf) is 0, therefore the change in kinetic energy becomes ΔKE =
- 0 = 392 J
\frac{-(ΔKE+ΔU)}{h}[/tex] = 
= 
= 212.33 N
Answer:
2.75 meters.
Explanation:
1 meter = 100 centimeters.
There are 275 centimeters.
275/100=2.75
So, each piece of wallpaper was 2.75 meters long.
When a neutron or a proton in the nucleus changes a gamma ray is produced (gamma rays are electromagnetic waves)
When an electron drops from a higher energy level to a lower energy level an electromagnetic wave is give off.
To solve this problem it is necessary to apply the concepts related to the change of Energy in photons and the conservation of energy.
From the theory we could consider that the energy change is subject to
Where
Initial Energy
Energy loses
Replacing we have that
Therefore the Kinetic energy of the electron once it has broken free of the metal surface is 0.8eV
