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A first piece of rock which weighs 5N. Force F is applied to this first piece of rock and it produces an acceleration of a. Now if there is a second piece of rock. What force needs to be applied to the second piece of rock to produce an acceleration of 8a. Mass of both pieces of rock is same.

User Sophie Alpert
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2 Answers

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13 votes

Answer:

Step-by-step explanation:

he force will depend on the masses of the rocks.

The formula you weren’t paying attention to in your Physics lesson was one of the more basic ones:

F = ma

F is the force. m is the mass of the object, and a is the acceleration. That’s all you should need.

Unfortunately, your question gave the weight of the rocks, not their masses. So, it can’t be answered without more information - eg is the rock on Earth, or on the moon, Mars or a planet orbiting Alpha Centauri?

If the rock is located on Earth, then you can use the same formula as above, because we know that a = g = 9.8m/s/s. and F is the weight. So, we know F, a and can work out m using a bit of basic algebra.

The other problem is that we don’t know the mass of the second piece of rock, because we haven’t been told either the weight or mass of that piece of rock.

If your homework question didn’t specify that, you can either refuse to answer it saying that not enough information was given, or STATE in your answer that you are assuming that the second piece of rock is the same mass as the first one.

If you decide to do that, then a minute’s work should give you the answer you’re looking for.

User Pylover
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16 votes
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The force needed to produce an acceleration of 8a on the second piece of rock is 40N.

To find the force needed to produce an acceleration of 8a on the second piece of rock, we can use Newton's second law of motion which states that force (F) is equal to mass (m) multiplied by acceleration (a).

Given that the mass of both pieces of rock is the same, we can set up the following equation:

F = m * (8a)

Simplifying, we get:

F = 8ma

Since the force required to produce an acceleration of a on the first piece of rock is 5N, we can substitute the values:

5N = ma

Solving for m, we get:

m = 5N/a

Substituting this value into the equation for the force on the second piece of rock, we get:

F = 8(5N/a)a

Simplifying further,

F = 40N

The force needed to produce an acceleration of 8a on the second piece of rock is 40N.

User DedObed
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