The average density of the material from which the coin is made is 9.67 g/cm³.
<h3>Volume of the coin</h3>
The volume of the coin at the given diameter is calculated as follows;
V = Ah
where;
- A is area of the coin
- h is the thickness of the coin
V = πd²/4 x h
V = π(2.8)²/4 x (0.21 cm)
V = 1.293 cm³
<h3>average density of the coin</h3>
The average density of the material from which the coin is made is calculated as follows;
density = mass/volume
density = 12.5 g / (1.293 cm³)
density = 9.67 g/cm³
Thus, the average density of the material from which the coin is made is 9.67 g/cm³.
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Answer:
Part 1)
Boat A will win the race
Part 2)
Boat A will win the race by 48 km as the 2nd boat will reach the other end while boat A will just touches the finish line
Part 3)
average velocity must be zero
Explanation:
As we know that the distance moved by the boat is given as

now the time taken by the boat to move to and fro is given as



Time taken by Boat B to cover the distance


Part 1)
Boat A will win the race
Part 2)
Boat A will win the race by 48 km as the 2nd boat will reach the other end while boat A will just touches the finish line
Part 3)
Since the displacement of Boat A is zero
so average velocity must be zero
Answer:
1.5 km/s²
Explanation:
Given that:
a car starts from rest; it means the initial velocity (u) = 0 km/hr = 0 m/s
after time (t) = 20 seconds
the final velocity = 108 km/hr = 30 m/s
The acceleration (a) of the car can be determined by using the formula:



a = 1.5 km/s²
When the student the sled jumps off toward the north , the sled most likely move towards the south.
<h3>What is the Newton third law?</h3>
According to the Newton third law of motion, action and reaction are equal and opposite. This means that the direction of the reaction force must also be opposite to that of the action.
As such, when the student the sled jumps off toward the north , the sled most likely move towards the south.
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Answer: b
Explanation:
When heat is released by the system i.e. system loses heat. So, we take it as negative -Q
When the work is done on the system then it is considered as negative work on the system i.e. -W
In this case, the plunger is pulled out, and work is done on the system. So, we take work as negative work -W
Correct option is b