Answer:
D. The motion cannot be determined without knowing the speeds of the objects before the collision.
Explanation:
This question is tricky! We know the object moving to the left has a greater mass than the one moving to the right. We'd <em>assume</em> they would move to the left because the leftwards object has a greater mass, right?
Not. So. Fast.
We can solve for the objects' final velocity using the formula for momentum, m₁v₁ + m₂v₂ = (m₁ + m₂)v .
Now here's where the trap is sprung: <em>we don't think about the equation</em>. This shows that the final velocity of the objects and the direction depends on both the mass of the objects <em>and</em> their initial velocity.
Basically, what if the 3 kg object is moving at 1 m/s and the 4 kg object is moving at –0.5 m/s? The objects would move to the <em>right</em> after the collision!
Do we know the velocity of these objects? No, right?
That means we <em>can't</em> determine the direction of their motion <u>unless we know their initial, pre-collision velocity</u>. This question is tricky because we look at the 4 kg vs. 3 kg and automatically assume the 4 kg object would dictate the direction of motion. That's not true. It depends on velocity as well.
I hope this helps you! Have a great day!
The ball took half of the total time ... 4 seconds ... to reach its highest
point, where it began to fall back down to the point of release.
At its highest point, its velocity changed from upward to downward.
At that instant, its velocity was zero.
The acceleration of gravity is 9.8 m/s². That means that an object that's
acted on only by gravity gains 9.8 m/s of downward speed every second.
-- If the object is falling downward, it moves 9.8 m/s faster every second.
-- If the object is tossed upward, it moves 9.8 m/s slower every second.
The ball took 4 seconds to lose all of its upward speed. So it must have
been thrown upward at (4 x 9.8 m/s) = 39.2 m/s .
(That's about 87.7 mph straight up. Somebody had an amazing pitching arm.)
<h2>Answer:</h2>
All the energy sources are correctly matched with their category.
Explanation:
Renewable energy sources:
These are energy sources which can be replenished as they don't in involves the irreversible phase change.
These resources can never be ended as they can be used again and again.
Wind, geothermal, biomass, bio gas are example of renewable energy sources.
Non renewable energy sources:
These are the energy source which can never be replenished after one time use. They undergo the chemical irreversible change.
These sources are lacking with the passage of time because they can never be reused.
Oil, gas, coal and natural gas are examples.
Initial velocity (u) = 2 m/s
Acceleration (a) = 10 m/s^2
Time taken (t) = 4 s
Let the final velocity be v.
By using the equation,
v = u + at, we get
or, v = 2 + 10 × 4
or, v = 2 + 40
or, v = 42
The final velocity is 42 m/s.
