Electron affinity is the tendency of a metal to accept electrons. In a general battery, one terminal has a higher electron affinity than the other, which attracts more electrons towards it, as compared to the other terminal. This potential difference between terminals create the voltage of the battery.
Answer:

Explanation:
Work is the product of force and distance.

We know the force to lift the rock was 50 Newtons. The work was 150 Joules.
- 1 Joule is equal to 1 Newton meters.
- We can convert the units to make the problem simpler later. The work is also 150 Newton meters.

Substitute the values into the formula.

We want to solve for distance, so we must isolate the variable. Divide both sides of the equation by 50 Newtons.

The Newtons will cancel out.

The rock was lifted <u>3 meters.</u>
Answer:
b. B
Explanation:
Picture B has the smallest peaks among all which henceforth makes the wavelength i.e. distance between two adjacent crests or troughs, small.
Answer:
4.2 km
Explanation:
A triangle is a polygon with three sides and three angles. There are different types of triangles such as isosceles triangle, scalene triangle, equilateral triangle and right angled triangle.
Sine rule states that for a triangle with angles A,B and C and corresponding opposite sides a, b, and c, the following formula holds:

Let the starting point be A, hence the side opposite to the angle = a = distance travelled in north east direction.
Let the point of 60° of northeast be B = 90° + (90° - 60°) = 120°, hence the side opposite to the angle = b = resultant displacement = 8 km.
Let C be the endpoint, hence the side opposite to the angle = c = distance travelled north = 5 km
Using sine rule:

∠A + ∠B + ∠C = 180° (sum of angle in a triangle)
∠A + 120 + 32.8 = 180
∠A = 27.2°

Therefore she travelled 4.2 km in the north east direction