A toy cannon uses a spring to project a 5.30-g soft rubber ball. The spring is originally compressed by 5.00 cm and has a force constant of 8.00 N/m. When the cannon is fired, the spring decompresses and returns to its equilibrium length, causing the ball to speed up, before the ball enters the horizontal barrel of the cannon. The horizontal barrel is 15.0 cm long and it exerts a constant friction force of 0.032 N on the ball. A. With what speed does the projectile leave the barrel of the cannon

Respuesta :

Answer:

1.40 m/s

Explanation:

The potential energy of a compressed spring can be expressed as:

[tex]E_{ps}=\dfrac{1}{2}kx^2[/tex]

From above;

k = spring constant

x = distance of the spring (compressed)

From the barrel, the kinetic energy (i.e. the final K.E) of the ball is calculated using the relation:

[tex]E_{kf}= \dfrac{1}{2}mv^2[/tex]

where;

m = the ball mass

v = ball's speed

Equating both equations above, we have:

[tex]E_{ps}- F_fd=E_{kf[/tex]

This can be re-written as:

[tex]\dfrac{1}{2}kx^2 - F_fd=\dfrac{1}{2}mv^2}[/tex]

[tex]v^2 = (\dfrac{k}{m})x^2-\dfrac{2F_fd}{m}[/tex]

[tex]v =\sqrt{ (\dfrac{k}{m})x^2-\dfrac{2F_fd}{m}}[/tex]

replacing the values from the given information:

[tex]v =\sqrt{ (\dfrac{8.00\ N/m}{5.30\times10^{-3} \ kg})(5.00 \ cm \times \dfrac{10^{-2} \ m}{1 \ cm})^2-(\dfrac{2(0.032 \ N)(0.150 \ m)}{5.30\times \dfrac{10^{-3} \ kg}{1 \ g}})}[/tex]

[tex]v = \sqrt{1.962264151}[/tex]

v ≅ 1.40 m/s

The speed at which the projectile leaves the barrel of the cannon will be given as [tex]v=1.40\ \frac{m}{s}[/tex]

What is speed?

Speed is defined as the movement of any object with respect to time. It is the ratio of distance and time.

Now it is given in the question:

Mass of ball m = 5.30 g

The deflection of spring = 5 cm

The force constant of spring  [tex]k= 8 \ \frac{N}{m^2}[/tex]

The length of the barrel = is 15 cm

The frictional force of the barrel = 0.032 N

Now from the conservation of energy, we can write as

[tex]E_{spring}-E_{friction}=E_{ball}[/tex]

[tex]\dfrac{1}{2} kx^2-F_fd=\dfrac{1}{2} mv^2[/tex]

[tex]v=\sqrt{\dfrac{k}{m}(x^2) -\dfrac{2F_fd}{m} }[/tex]

Now putting the values in the above formula:

[tex]v=\sqrt{\dfrac{8}{5.30\times 10^{-3}}(15\times10^{-2}) -\dfrac{2\times(0.0032)\times (0.015)}{5.30\times 10^{-3}} }[/tex]

[tex]v=1.40\ \frac{m}{s}[/tex]

Thus the speed at which the projectile leaves the barrel of the cannon will be given as [tex]v=1.40\ \frac{m}{s}[/tex]

To know more about the Speed of projectile follow

https://brainly.com/question/706354