Answer:
b. Hill top
Explanation:
On a topographic map, the closed circles are meant to represent a hill. So if the contour lines are creating a group of concentric closed loops then it must be an indication of a hill.
It depends whether or not the object in moving relative or not to the reference point, for instance imagine a void where there were no dimensions, but there was an object. You can’t tell if the object is moving or not without a reference point.
3.11 is the answer I think
Average force is 666.67 N
<u>Explanation:</u>
Given that :
m = Mass of the baseball = 0.2 kg
u = Initial velocity = 20 m/s
v = Final velocity = 40 m/s
t = Time taken for change in velocity = 0.006 s
We know:
Force exerted = mass × acceleration = m ×a
Acceleration can be found by means of dividing the change in velocity measured in m/s by the time taken in seconds.
a =
=
m/s²
Now we have to find the force using the formula, F = mass × acceleration as,
F = 0.2 kg ×3333.3 ms⁻² = 666.67 N