Answer:
The velocity of a falling object
Explanation:
The positive X axis is towards right and positive Y axis is towards up, so North direction is positive
A vector with less than 1 magnitude is not negative, because its magnitude may be in between 0 and 1 which is positive vector.
Any vector whose magnitude is greater than 1 is never be a negative vector.
The velocity of a falling object is towards bottom, that is towards negative Y axis. So that vector is negative.
If an atom gains electrons, it develops a negative charge equal to the number of electrons gained.
So the net charge on the copper atom which gained 2 electrons will be -2.
The speed of the ball moving is

what is momentum?
The momentum p of a classical object of mass m and velocity v is given by pclassical =mv.
For photons with wavelength λ,this equation does not hold.Instead, the momentum of the Photon is given by p Photon = h/λ
where,h is the planck's constant.
The momentum of the red Photon is
given:




since,the Photon and the ping-pong ball have the same momentum,we have



Therefore, if the red photon and the ping-pong ball have the same momentum, the ping-pong ball must have a speed of approximately

learn more about momentum of photon from here: brainly.com/question/28197406
#SPJ4
Answer:
Q = - 4312 W = - 4.312 KW
Explanation:
The rate of heat of the concrete slab can be calculated through Fourier's Law of heat conduction. The formula of the Fourier's Law of heat conduction is as follows:
Q = - kA dt/dx
Integrating from one side of the slab to other along the thickness dimension, we get:
Q = - kA(T₂ - T₁)/L
Q = kA(T₁ - T₂)/t
where,
Q = Rate of Heat Loss = ?
k = thermal conductivity = 1.4 W/m.k
A = Surface Area = (11 m)(8 m) = 88 m²
T₁ = Temperature of Bottom Surface = 10°C
T₂ = Temperature of Top Surface = 17° C
t = Thickness of Slab = 0.2 m
Therefore,
Q = (1.4 W/m.k)(88 m²)(10°C - 17°C)/0.2 m
<u>Q = - 4312 W = - 4.312 KW</u>
<u>Here, negative sign shows the loss of heat.</u>