It is b exothermic cause it in a system increases the reaction is considered to be b.
Answer:
Candles
Explanation:
The answer is the first option or "candles." In ancient times the people would lit candles and place them in difference places in their homes, temples, etc... to produce light. It's not option B because light emitting diodes are used to light up toys and such which weren't invented in ancient times. It's not option C because fluorescent bulbs are long light bulbs used to light up huge spaces without as many light bulbs which were again not invented at the time, and it's also not option D because incandescent bulbs are you usual light bulbs which weren't invented at the time.
Hope this helps.
We can see it as two movements: one on the north-south axis and one on the west-east axis.
On the north-south Axis, the hiker went 8 km north and 4 km south, so in total the hiker went 4 km north (we can subtract one for the other and the direction remains that which was bigger)
On the west-easth Axis, the hiker went 6 km east and 6 km west, so in total the hiker didn't move on this axis! or, he/she moved but then "came back"
So in total, the hiker only moved4 km north - answer B.
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The horizontal force applied is 160 N while the velocity is 2.03 m/s.
<h3>What is the speed of the car?</h3>
The work done by the car is obtained as the product of the force and the distance;
W = F x
F = ?
x = 30.0 m
W = 4,800 J
F = 4,800 J/30.0 m
F = 160 N
But F = ma
a = F/m
a = 160 N/2.30 ✕ 10^3-kg
a= 0.069 m/s
Now;
v^2 = u^2 + 2as
u = 0/ms because the car started from rest
v = √2as
v = √2 * 0.069 * 30
v = 2.03 m/s
Learn more about force and work:brainly.com/question/758238
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