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2 years ago

A stone is projected horizontally from the

Physics

1 answer:

Nadya [2.5K]2 years ago

6 0

Answer:

80 m tall

Explanation:

*** EDITED *** (I left out the '1/2' in the equation....D'Oh!)

It was descending 4 seconds ...because it landed 20 m away (at 5 m/s ...so 4 seconds)

displacement =<u> 1/2</u> a t^2

= 1/2 * 10 ( 4)^2 = 80 m tall

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14. Three identical light bulbs are connected in series, then are disconnected and arranged in parallel. For each of the scenari

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3 years ago

You are watching an archery tournament when you start wondering how fast an arrow is shot from the bow. Remembering your physics

spayn [35]

Answer:

$v_0 = 3.53~{\rm m/s}$

Explanation:

This is a projectile motion problem. We will first separate the motion into x- and y-components, apply the equations of kinematics separately, then we will combine them to find the initial velocity.

The initial velocity is in the x-direction, and there is no acceleration in the x-direction.

On the other hand, there no initial velocity in the y-component, so the arrow is basically in free-fall.

Applying the equations of kinematics in the x-direction gives

$x - x_0 = v_{x_0} t + \frac{1}{2}a_x t^2\\63 \times 10^{-3} = v_0t + 0\\t = \frac{63\times 10^{-3}}{v_0}$

For the y-direction gives

$v_y = v_{y_0} + a_y t\\v_y = 0 -9.8t\\v_y = -9.8t$

Combining both equation yields the y_component of the final velocity

$v_y = -9.8(\frac{63\times 10^{-3}}{v_0}) = -\frac{0.61}{v_0}$

Since we know the angle between the x- and y-components of the final velocity, which is 180° - 2.8° = 177.2°, we can calculate the initial velocity.

$\tan(\theta) = \frac{v_y}{v_x}\\\tan(177.2^\circ) = -0.0489 = \frac{v_y}{v_0} = \frac{-0.61/v_0}{v_0} = -\frac{0.61}{v_0^2}\\v_0 = 3.53~{\rm m/s}$

6 0

3 years ago

A spring with k = 53 N/m hangs vertically next to a ruler. The end of the spring is next to the 18 cm mark on the ruler. If a 2.

Anarel [89]

Answer:

1.07 m

Explanation:

x = Compression of the spring

k = Spring constant = 53 N/m

Initial length = 18 cm

P = Kinetic energy

K = Kinetic energy

At the lowest point of the mass the energy conservation is as follows

$P_{ig}+P_{is}+K_i=P_{fg}+P_{fs}+K_f\\\Rightarrow mgx+0+0=mgx+\frac{1}{2}kx^2\\\Rightarrow x=\frac{2mg}{k}\\\Rightarrow x=\frac{2\times 2.4\times 9.81}{53}\\\Rightarrow x=0.89\ m$

At its lowest position the mark on the ruler will be

$x_f=0.18+0.89\\\Rightarrow x_f=1.07\ m$

The spring line will end up at 1.07 m

4 0

3 years ago