If I remember correctly, it is the 3rd answer choice.
Answer:
That is, mechanical waves cannot travel through a vacuum. This feature of mechanical waves is often demonstrated in a Physics class. A ringing bell is placed in a jar and air inside the jar is evacuated. Once air is removed from the jar, the sound of the ringing bell can no longer be heard.
Answer:
Velocity of Pauli relative to Daniel = (-1.50ï + 3.90ĵ) m/s
x-component = -1.50 m/s
y-component = 3.90 m/s
Explanation:
Relative velocity of a body A relative to another body B, Vab, is given as
Vab = Va - Vb
where
Va = Relative velocity of body A with respect to another third body or frame of reference C
Vb = Relative velocity of body B with respect to that same third body or frame of reference C.
So, relative velocity can be given further as
Vab = Vac - Vbc
Velocity of Newton relative to Daniel = Vnd = 3.90 m/s due north = (3.90ĵ) m/s in vector form.
Velocity of Newton relative to Pauli = Vnp = 1.50 m/s due East = (1.50î) m/s in vector form
What is Pauli's velocity relative to Daniel?
Vpd = Vp - Vd
(Pauli's velocity relative to Daniel) = (Pauli's velocity relative to Newton) - (Daniel's velocity relative to Newton)
Vpd = Vpn - Vdn
Vpn = -Vnp = -(1.50î) m/s
Vdn = -Vnd = -(3.90ĵ) m/s
Vpd = -1.50î - (-3.90ĵ)
Velocity of Pauli relative to Daniel = (-1.50ï + 3.90ĵ) m/s
Hope this Helps!!!!
From that particular list:
Mica (A), Quartz (B), and Copper (D) are minerals.
Steam (C) isn't.
Answer:
Tension, T = 0.0115 N
Explanation:
Given that,
Mass of the plastic ball, m = 1.1 g
Length of the string, l = 56 cm
A charged rod brought near the ball exerts a horizontal electrical force F on it, causing the ball to swing out to a 21.0 degree angle and remain there. According to attached figure :

T is tension in the string

So, the tension in the string is 0.0115 N.