I have a question involving the spring costant:

A 2-kg block is attached to a horizontal ideal spring with a spring constant of 200N/m. When the spring has its equilibrium length the block is given a speed of 5 m/s. What is the maximum elongation of the spring? The answer is supposed to be in m.
I used 1/2mv^2=1/2KX^2, the answer I get is .5m which doesn't seem right.

Thank you

The word equilibrium is confusing here, so I am assuming as you did that the equilibrium length for a horizontal spring is its stretched length.

You used the correct relationship: max PE equals starting KE.
then if follows
x= v/sqrt k

I don't get your answer, I get less.

did u get .05m? i don't why i am getting that now

.

Yes, you should get 0.05 m. The equation is 1/2mv^2 = 1/2kx^2, so x = v/sqrt(k). Plugging in the values, you get x = 5/sqrt(200) = 0.05 m.

To find the maximum elongation of the spring, you can use the equation you mentioned, which is the conservation of mechanical energy equation:

1/2mv^2 = 1/2kx^2

where m is the mass of the block (2 kg), v is the velocity of the block (5 m/s), k is the spring constant (200 N/m), and x is the maximum elongation of the spring.

To solve for x, rearrange the equation:

x^2 = (mv^2) / k

x^2 = (2 kg * (5 m/s)^2) / 200 N/m

x^2 = (2 kg * 25 m^2/s^2) / 200 N/m

x^2 = 0.25 m^2

Taking the square root of both sides gives:

x = sqrt(0.25) m

x = 0.5 m

Therefore, the maximum elongation of the spring is 0.5 meters.

It seems that your initial calculation of 0.5 m is correct. Make sure to double-check your calculations to ensure accuracy.

To find the maximum elongation of the spring, we can use the equation:

Potential Energy (PE) = Kinetic Energy (KE)

Given:
Mass (m) = 2 kg
Spring constant (k) = 200 N/m
Speed (v) = 5 m/s

The equation for potential energy in a spring is:

PE = 1/2 * k * x^2

The equation for kinetic energy is:

KE = 1/2 * m * v^2

Setting PE equal to KE:

1/2 * k * x^2 = 1/2 * m * v^2

Substituting the given values:

1/2 * 200 * x^2 = 1/2 * 2 * 5^2

Simplifying:

100 * x^2 = 10 * 25
100 * x^2 = 250

Dividing both sides by 100:

x^2 = 2.5

Taking the square root of both sides:

x = √2.5

Simplifying:

x ≈ 1.58 m

Therefore, the maximum elongation of the spring is approximately 1.58 m.