Answer:
The angle between the electric field lines and the equipotential surface is 90 degree.
Explanation:
The equipotential surfaces are the surface on which the electric potential is same. The work done in moving a charge from one point to another on an equipotential surface is always zero.
The electric field lines are always perpendicular to the equipotential surface.
As
For equipotential surface, dV = 0 so
The dot product of two non zero vectors is zero, if they are perpendicular to each other.
The answer is A. Polarized in a vertical plane
If positioned correctly, a polarized lenses can block all reflected light from horizontal surface such as road
Answer:
20 m/s
30 m/s
Explanation:
Given:
v₀ = -10 m/s
a = -9.8 m/s²
When t = 1 s:
v = v₀ + at
v = (-10 m/s) + (-9.8 m/s²) (1 s)
v = -19.8 m/s
When t = 2 s:
v = v₀ + at
v = (-10 m/s) + (-9.8 m/s²) (2 s)
v = -29.6 m/s
Rounded to one significant figures, the speed of the ball at 1 s and 2 s is 20 m/s and 30 m/s, respectively.
The mass of ice melted as a result of friction between the ice and the horizontal surface is 2.78g
<u>Explanation:</u>
Given,
Temperature, T = 0°C
Initial mass, Mi = 62kg
Speed, s = 5.48m/s
Distance, x = 26.8m
Friction is present.
Mass of ice melted = ?
We know,
The amount of energy required for the melting of ice is exactly equal to the initial kinetic energy of the block of ice
and
Therefore, 
KE = 930.94 Joules
Ice melting lateral heat is 334 kJ/kg = 334000 J/kg.
Therefore, the melted mass of the ice = 930.94 / 334000 = 0.00278 kg = 2.78 g.
Thus, The mass of ice melted as a result of friction between the ice and the horizontal surface is 2.78g
