Answer:
0.733J/g°C
Explanation:
Using the formula
Q=mcΔθ
Q=38.5J, c=? , m=17.5g , Δθ=3°C
c= Q/(mΔθ)
c=0.733J/g°C
Answer: 1. B. The number of electrons emitted from the metal per second increases.
2. The maximum speed of the emitted electrons increases.
The stopping potential increases
Explanation:
Photoelectric effect is simply referred to as the emission of electrons that occurs when there's an electromagnetic radiation. An example of such electromagnetic radiation is when material is being hit by light.
Assuming that the light incident on the metal surface causes electrons to be ejected from the metal, the number of electrons emitted from the metal per second increases if the intensity of the incident light is increased.
Also, if the initial light incident on the metal surface causes electrons to be ejected from the metal, the maximum speed of the emitted electrons increases and the stopping potential increases.
In the vertical direction, take up to be positive and down to be negative. Then the net <u>vertical</u> force would be
5120 N - 4050 N = 1070 N
(it's positive, so the net vertical force is pointing upward)
In the horizontal direction, take right to be positive and left to be negative. Then the net <u>horizontal</u> force would be
950 N - 1520 N = -570 N
(negative means the net horizontal force points to the left)
So the net force on the balloon is the vector
<em>F</em> = (1070 N) <em>i</em> + (-570 N) <em>j</em>
(where <em>i</em> and <em>j</em> are the unit vectors in the horizontal and vertical directions, respectively)
The magnitude of the net force on the balloon is the magnitude of this vector:
<em>F</em> = √((1070 N)² + (-570 N)²)
<em>F</em> ≈ 1212 N
The cart is at rest, so it is in equilibrium and there is no net force acting on it. The only forces acting on the cart are its weight (magnitude <em>w</em>), the normal force (mag. <em>n</em>), and the friction force (maximum mag. <em>f</em> ).
In the horizontal direction, we have
<em>n</em> cos(120º) + <em>f</em> cos(30º) = 0
-1/2 <em>n</em> + √3/2 <em>f</em> = 0
<em>n</em> = √3 <em>f</em>
and in the vertical,
<em>n</em> sin(120º) + <em>f</em> sin(30º) + (-<em>w</em>) = 0
<em>n</em> sin(120º) + <em>f</em> sin(30º) = (50 kg) (9.80 m/s²)
√3/2 <em>n</em> + 1/2 <em>f</em> = 490 N
Substitute <em>n</em> = √3 <em>f</em> and solve for <em>f</em> :
√3/2 (√3 <em>f </em>) + 1/2 <em>f</em> = 490 N
2 <em>f</em> = 490 N
<em>f</em> = 245 N
(pointed up the incline)
<span>Density can be determined by the
mass of an object and how much it takes up space (volume). It is represented by
the formula D = M/V where D is the density in kg/m^3 or lb/ft^3, M is the mass
in kg or lb and V is the volume in m^3 or ft^3. The answer would be A. For example, you are given the mass of an
object of 40.5kg and a volume of 15m^3. Find its density.</span>
D = M/V
D = (40.5 kg)
/ (15 m^3)
<span>D = 27/10 or
2.7 kg/m^3 </span>
