Answer:
The velocity of the boat with respect to the ground is 3 km/h
Explanation:
The speed of an object is different depending on the reference system you use. This is called relative speed.
A boat travels upstream, this means that it moves in the opposite direction to the river current.
A boat travels upstream, this means that it moves in the opposite direction to the river current. Then, if the boat moves in the positive direction of the x axis at 10 km / h with respect to the water of a river, the water flows in the negative direction of the x axis at 7 km / h with respect to the ground.
This causes the speed of the boat relative to the ground to be calculated as follows:
<em>VbG = Vbw - VwG
</em>
where VbG is the speed of the boat relative to the ground, Vbw is the speed of the boat relative to the water of the river and VwG is the speed of the water relative to the ground.
So: VbG=10 km/h – 7 km/h
<u><em>VbG= 3 km/h
</em></u>
The direction of this velocity is in the positive x-direction.
Answer:
Explanation:
Given
Free fall acceleration on mars 
Time Period of pendulum on earth 
Time period of Pendulum is given by

for earth



(b)For same time period on mars length is given by



<span>C. Does eating less fat increase a mouse's lifespan?
(If a mouse eats less fat in its meals then will it live longer: compared to other mice lives.
</span>This is a testable question that can be answered by designing and conducting an experiment.
I think D could be correct as well.
My final answer is D.
(a) The distance of the image formed by the concave mirror is 19.1 cm.
(b) The image formed is diminished and real.
<h3>
Image distance </h3>
The distance of the image formed by the concave mirror is calculated as follows;
1/f = 1/v + 1/u
1/v = 1/f - 1/u
1/v = 1/15 - 1/70
1/v = 0.05238
v = 1/0.05238
v = 19.1 cm
The image distance is smaller than object distance, thus the image formed is diminished and real.
Learn more about concave mirror here: brainly.com/question/13164847
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