Answer:
No temperature change occurs from heat transfer if ice melts and becomes liquid water (i.e., during a phase change). For example, consider water dripping from icicles melting on a roof warmed by the Sun. Conversely, water freezes in an ice tray cooled by lower-temperature surroundings.
Explanation:
Energy is required to melt a solid because the cohesive bonds between the molecules in the solid must be broken apart such that, in the liquid, the molecules can move around at comparable kinetic energies; thus, there is no rise in temperature. Similarly, energy is needed to vaporize a liquid, because molecules in a liquid interact with each other via attractive forces. There is no temperature change until a phase change is complete. The temperature of a cup of soda initially at 0ºC stays at 0ºC until all the ice has melted. Conversely, energy is released during freezing and condensation, usually in the form of thermal energy. Work is done by cohesive forces when molecules are brought together. The corresponding energy must be given off (dissipated) to allow them to stay together Figure 2.
The energy involved in a phase change depends on two major factors: the number and strength of bonds or force pairs. The number of bonds is proportional to the number of molecules and thus to the mass of the sample. The strength of forces depends on the type of molecules. The heat Q required to change the phase of a sample of mass m is given by
Q = mLf (melting/freezing,
Q = mLv (vaporization/condensation),
where the latent heat of fusion, Lf, and latent heat of vaporization, Lv, are material constants that are determined experimentally.
Answer:
m=146.277kg which is rounded to 146kg
Explanation:
Remember that F=ma
But F represents not 250N, but 250cos(35)N since the force is being pulled above the horizontal.
So 250cos(35)=204.7880111 approximately, and since a=1.4m/s^2, we have 204.7880111=m(1.4m/s^2). Then we divide both sides by the acceleration to get the mass. So m=146.2771508kg which the nearest number is 146kg
Mass is always in kg, unless stated otherwise.
I am pretty sure the answer to your question is B
Answer:
4.25 J
Explanation:
Given that
mass of plastic ball = 11 g
Mass of plastic ball = 0.011 kg
velocity of ball = 29 m/s
We know that from work power energy theorem
We know that kinetic energy of moving mass given as
Now by pitting the values
KE= 4.25 J
So the work done on the ball is 4.25 J
Answer:
106.03 meters
Explanation:
The height is given by the formula for motion under the influence of gravity.
h = -4.9t^2 +162.7
Height is 0 when ...
0 = -4.9t^2 +162.7
4.9t^2 = 162.7
t^2 = 162.7/4.9
t = √(162.7/4.9)
The horizontal distance traveled in that time is ...
(18.4 m/s)√(162.7/4.9) s ≈ 106.03 m
The object will strike the ground about 106.03 meters from the base of the cliff.
