Answer:
a. closer to 20∘C
Explanation:
= mass of pallet = 50 g = 0.050 kg
= specific heat of pallet = specific heat of iron
= Initial temperature of pellet = 200 C
= mass of water = 50 g = 0.050 kg
= specific heat of water
= Initial temperature of water = 20 C
= Final equilibrium temperature
Also given that
Using conservation of energy
Energy gained by water = Energy lost by pellet
hence the correct choice is
a. closer to 20∘C
<span>Answer:
First we need to find the acceleration.
torque on cylinder Ď„ = T * r where T is the string tension;
T = m(g - a) where a is the acceleration of the cylinder. Then
Ď„ = m(g - a)r
But also τ = Iα. For a solid cylinder, I = ½mr²,
and if the string doesn't slip, then α = a / r, so
τ = ½mr² * a/r = ½mra.
Since Ď„ = Ď„, we have
m(g - a)r = ½mra → m, r cancel, leaving
g - a = ½a
g = 3a/2
a = 2g/3 where g, of course, is gravitational acceleration.
We know that v(t) = a*t, so for our cylinder
v(t) = 2gt / 3 â—„ linear velocity
and ω = v(t) / r = 2gt / 3r ◄ angular velocity</span>
Answer: the sun
Explanation:
The sun's radiant energy reaches the earth's surface either directly through radiation, indirectly through convection, or it can move "across" or "through" objects or materials on the surface via conduction. Let's look more closely at each case. We've probably experienced the feeling of "warmth" of the sun on our skin on a sunny day. Light energy from the sun is reaching us across space and down through the atmosphere through radiation. A dark colored vehicle in the sun quickly becomes warm (or hot!) to the touch because of radiation. The light energy from the sun heats the air in the earth's atmosphere, and this drives convection and transfers thermal energy around. It is possible that we've felt a "hot breeze" on our skin on sunny days. The thermal energy in the air will be carried to objects in its path, and it will warm them.
Answer:
a = 40 [m/s²]
Explanation:
These kinds of problems can be solved using Newton's second law, which tells us that the sum of forces on a body is equal to the product of mass by acceleration.
∑F = m*a
where:
F = force = 6 [N]
m = mass = 0.15 [kg]
a = acceleration [m/s²]
![a=F/m\\a=6/0.15\\a=40[m/s^{2} ]](https://tex.z-dn.net/?f=a%3DF%2Fm%5C%5Ca%3D6%2F0.15%5C%5Ca%3D40%5Bm%2Fs%5E%7B2%7D%20%5D)
