Their average velocity is 0.98 m/s east.
Explanation:
The average velocity of an object is defined as the ratio between the displacement and the time taken:

The displacement is a vector connecting the initial point to the final point of motion: so, being displacement a vector, velocity is a vector as well, having the same direction of displacement.
Here, Heather and Matt walk 2.0 km eastward, so their displacement is
d = 2.0 km = 2000 m (east)
While the time they took is

Therefore, their average velocity is

And the direction is the same as the displacement (east).
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Answer:
40479.6 J
Explanation:
Applying,
q = cm(t₂-t₁).................... Equation 1
Where q = change in heat content of the system, c = specific heat capacity of the system, m = mass of the system, t₁ = initial temperature, t₂ = final temperature.
From the question,
Given: m = 79 g = 0.079 kg, t₁ = 21°C, t₂ = 143°C
Constant: c = 4200 J/kg.°C
Substitute these values into equation 1
q = 4200(0.079)(143-21)
q = 331.8(122)
q = 40479.6 J
Well we know the correct answer cannot be "a" bcause velocity is tangent to the circlular path of an object experienting centripical motion. Velocity DOES NOT point inward in centripical motion.
we know the correct answer cannot be "b" because "t" stands for "time" which cannot point in any direction. so, time cannot point toward the center of a circle and therefore this answer must be incorrect.
I would choose answer choice "c" because both force and centripical acceleration point toward the center of the circle.
I do not think answer choice "d" can be correct because the velocity of the mass moves tangent to the circle. velocity = (change in position) / time. Therefore, by definition the mass is moving in the direction of the velocity which does not point to the center of the circle.
does this make sense? any questions?
I guess it is a: seismic waves
Answer:
Her average speed is 0.25 miles / hour.
Explanation:
I did 0.5 divided by 2 = 0.25 miles / hour.
<em>Hope this helps! :)</em>