Answer:
2. A 1 litre mug of hot chocolate at 75 degrees.
Explanation:
Thermal energy is directly proportional to mass, so as the mass increases, the thermal energy of the substance increases as well.
Answer:
1) D, 2) D, 3) B, 4) B, 5) C
Explanation:
You are asked to select the correct answer
1) The conservation of energy is one of the most important principles of physics that allows solving countless problems in life.
the correct answer is D
2) when a body falls, the gravitational potential energy is transformed into kinetic energy and both are transformed into thermal energy
the correct answer is D
3) When the gravitational potential energy is maximum, the kinetic energy is minimum and when the kinetic energy is maximum, the gravitational energy is minimum.
Correct answer B
4) speed is defined by
v = x / t
so the correct answer is B in the SI system
5) when we repeat a measurement several times, the random or statistical errors decrease, therefore the confidence of the measurement increases.
The correct answer is C
a = 7.8 m/s^2
Explanation:
Let Fnet = net force = ma
m = mass of the skydiver
a = acceleration caused by Fnet
W = weight = mg
f(air) = frictional force due to air resistance
Fnet = W - f(air)
= (100 kg)(9.8 m/s^2) - (200 N)
= 780 N
Therefore, the acceleration of the skydiver due to Fnet is
a = Fnet/m
= (780 N)/(100 kg)
= 7.8 m/s^2
Answer;
D. rocket engines are not dependent on oxygen from the air.
Explanation;
-Jet engines and rockets work on the same principle. They produce thrust through an internal pressure difference and, as explained by Newton’s Third Law of Motion, eject exhaust gases in an equal and opposite direction.
-The main difference between them is that jets get the oxygen to burn fuel from the air and rockets carry their own oxygen, which allows them to operate in space.
Additionally, Jet engines have two openings (an intake and an exhaust nozzle). Rocket engines only have one opening (an exhaust nozzle).
Answer:
Hearing loss due to sound energy damaging the nerve cells in the inner ear. Many animals behavior is influenced by sound energy. They learn to associate events with sounds, so they run when something crunches in the dry grass (might be a coyote), but won't be bothered by the sound of a waterfall. Mood is affected by sound energy. A wine glass can break with sound energy, if the frequency matches the resonant frequency of the wine glass and the amplitude is great enough (one Mythbusters show featured a professional singer who broke a wine glass with his voice without any amplification).
Sound energy causes the particles in the medium it is traveling through to vibrate.
Unlike sound electromagnetic waves can travel trough empty space
hope these different answers help
