Part (a): Velocity of the snowball
By conservation of momentu;
m1v1 + m2v2 = m3v3,
Where, m1 = mass of snowball, v1, velocity of snowball, m2 = mass of the hat, v2 = velocity of the hat, m3 = mass of snowball and the hat, v3 = velocity of snowball and the hut.
v2 = 0, and therefore,
85*v1 + 0 = 220*8 => v1 = 220*8/85 = 20.71 m/s
Part (b): Horizontal range
x = v3*t
But,
y = vy -1/2gt^2, but y = -1.5 m (moving down), vy =0 (no vertical velocity), g = 9.81 m/s^2
Substituting;
-1.5 = 0 - 1/2*9.81*t^2
1.5 = 4.905*t^2
t = Sqrt (1.5/4.905) = 0.553 seconds
Then,
x = 8*0.553 = 4.424 m
Answer:
15.8 V
Explanation:
The relationship between capacitance and potential difference across a capacitor is:

where
q is the charge stored on the capacitor
C is the capacitance
V is the potential difference
Here we call C and V the initial capacitance and potential difference across the capacitor, so that the initial charge stored is q.
Later, a dielectric material is inserted between the two plates, so the capacitance changes according to

where k is the dielectric constant of the material. As a result, the potential difference will change (V'). Since the charge stored by the capacitor remains constant,

So we can combine the two equations:

and since we have
V = 71.0 V
k = 4.50
We find the new potential difference:

Explanation:
A worker picks up the bag of gravel. We need to find the speed of the bucket after it has descended 2.30 m from rest. It is case of conservation of energy. So,

h = 2.3 m

So, the speed of the bucket after it has descended 2.30 m from rest is 6.71 m/s.
Answer:
A flame always point upwards because the flame's gas is hotter than the surrounding air and, like you said, a hot gas is always lighter or less dense than a cold gas.
Explanation:
They do. mostly because they want validation from others