Answer:

Explanation:
Given that,
The initial speed of a car, u = 0
Time, t = 18 s
Distance, d = 390 m
We need to find the acceleration of the car. Let it is a. Using the second equation of motion to find it.

or

So, the acceleration of the car is
.
Answer:
The answer is "Choice E".
Explanation:
In this situation the option e is right because its resistance decreases through time, however, the time is the same for the same reason, whereas the sphere deteriorates, somehow it travels shorter distances however if the air resistance becomes are using the amplitude of movement declines, that's why other choices were wrong.
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.
Learn more about average density here: brainly.com/question/1354972
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<h2><em>So there is two truths given. After an amount of time Ttotal (lets call it ‘t’):
</em></h2><h2><em>
</em></h2><h2><em>The car’s speed is 25m/s
</em></h2><h2><em>The distance travelled is 75m
</em></h2><h2><em>Then we have the formulas for speed and distance:
</em></h2><h2><em>
</em></h2><h2><em>v = a x t -> 25 = a x t
</em></h2><h2><em>s = 0.5 x a x t^2 -> 75 = 0.5 x a x t^2
</em></h2><h2><em>Now, we know that both acceleration and time equal for both truths. So we can say:
</em></h2><h2><em>
</em></h2><h2><em>t = 25 / a
</em></h2><h2><em>t^2 = 75 / (0.5 x a) = 150 / a
</em></h2><h2><em>Since we don’t want to use square root at 2) we go squared for 1):
</em></h2><h2><em>
</em></h2><h2><em>t^2 = (25 / a) ^2 = 625 / a^2
</em></h2><h2><em>t^2 = 150 / a
</em></h2><h2><em>Since t has the same value for both truths we can say:
</em></h2><h2><em>
</em></h2><h2><em>625 / a^2 = 150 / a
</em></h2><h2><em>
</em></h2><h2><em>Thus multiply both sides with a^2:
</em></h2><h2><em>
</em></h2><h2><em>625 = 150 x a, so a = 625 / 150 = 4.17
</em></h2><h2><em>
</em></h2><h2><em>We can now calculate t as well t = 25 * 150 / 625 = 6</em></h2>
Answer:
<h2>507 J</h2>
Explanation:
The kinetic energy of an object can be found by using the formula

m is the mass
v is the velocity
From the question we have

We have the final answer as
<h3>507 J</h3>
Hope this helps you