The answer to the blank above is 20. The speed limit given provided that you cannot see the tracks for 400 ft in both directions is always 20 mph. Basically, this 20 mph is decided based upon the traffic laws in order to avoid road casualties. Since it is "uncontrolled railroad crossing", the minimum speed should be implemented to slow down for the purpose of traffic calming measures. Other than this, the 20 mph is also applicable in narrowing roads as well as speed humps.
Answer:
acceleration = 2.4525 m/s²
Explanation:
Data: Let m1 = 3.0 Kg, m2 = 5.0 Kg, g = 9.81 m/s²
Tension in the rope = T
Sol: m2 > m1
i) for downward motion of m2:
m2 a = m2 g - T
5 a = 5 × 9.81 m/s² - T
⇒ T = 49.05 m/s² - 5 a Eqn (a)
ii) for upward motion of m1
m a = T - m1 g
3 a = T - 3 × 9.8 m/s²
⇒ T = 3 a + 29.43 m/s² Eqn (b)
Equating Eqn (a) and(b)
49.05 m/s² - 5 a = T = 3 a + 29.43 m/s²
49.05 m/s² - 29.43 m/s² = 3 a + 5 a
19.62 m/s² = 8 a
⇒ a = 2.4525 m/s²
Answer:
The frequency of the photon decreases upon scattering
Explanation:
Here we note that when a photon is scattered by a charged particle, it is referred to as Compton scattering.
Compton scattering results in a reduction of the energy of the photon and hence an increase in the wavelength (from λ to λ') of the photon known as Compton effect.
Therefore, since the wavelength increases, we have from
λf = λ'f' = c
f = c/λ
Where:
f and f' = The frequency of the motion of the photon before and after the scattering
c = Speed of light (constant)
We have that the frequency, f, is inversely proportional to the wavelength, λ as follows;
f = c/λ
As λ = increases, and c is constant, f decreases, therefore, the frequency of the photon decreases upon scattering.
Answer:
Decreasing the distance between Hox and Blox, increasing the mass of Hox, or increasing the mass of Hox and Blox.
Explanation:
The gravity force is directly proportional to the mass of the bodies and inversely proportional to the square of the distance that separates them.
Or
If we decrease the distance between both planets (Hox and Blox), the gravitational pull between them will increase.
On the other hand, if we keep the distance between Hox and Blox, but we increase the mass of one of them, or increase the mass of both, the gravitational pull between them will also increase.
Answer:
ball clears the net
Explanation:
= initial speed of launch of the ball = 20 ms^{-1}
= angle of launch = 5 deg
Consider the motion of the ball along the horizontal direction
= initial velocity = 
= time of travel
= horizontal displacement of the ball to reach the net = 7 m
Since there is no acceleration along the horizontal direction, we have
Eq-1
Consider the motion of the ball along the vertical direction
= initial velocity = 
= time of travel
= Initial position of the ball at the time of launch = 2 m
= Final position of the ball at time "t"
= acceleration in down direction = - 9.8 ms⁻²
Along the vertical direction , position at any time is given as
Since Y > 1 m
hence the ball clears the net
