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

1.40 m/s

Explanation:

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

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:

where;

m = the ball mass

v = ball's speed

Equating both equations above, we have:

This can be re-written as:

replacing the values from the given information:

v ≅ 1.40 m/s

the maxium height is 34m/s

the speed of the cart after 3 seconds of low fan speed is ⇒ 54.0 cm/s.

the speed of the cart after 5 seconds of medium fan speed is ⇒ 120.0 cm/s.

the speed of the cart after 2 seconds of high fan speed is ⇒ 64.0 cm/s. 

just did the lab.