User's Manual

012-05479B Mini Launcher

Experiment 10 (Demo): Shooting Through Hoops

EQUIPMENT NEEDED

– Mini Launcher and steel ball – (5) Ring clamps on stands

– (2) Photogates – Photogate Bracket

– Meter stick – (2) Meter stick

– (optional) Computer with Timing software

Purpose

The purpose of this demonstration is to show that the path of a ball launched horizontally from a table is

parabolic.

Theory

The range is the horizontal distance, x, between the muzzle of the Launcher and the place where the ball

hits, given by

where v

is the initial speed of the ball as it leaves the muzzle and t is the time of flight.

The vertical position, y, of the ball at time t is given by

where y

is the initial height of the ball and g is the acceleration due to gravity.

Setup

➀ Before the demonstration begins, find the initial velocity for the range setting to be used. Attach the

photogates and use a computer to find the initial velocity or shoot the ball horizontally and measure x

and y to find the initial velocity. See experiments 1 and 2.

➁ To prepare the demonstration, clamp the Mini Launcher to the table with the Launcher aimed away from

the table so the ball will land on the floor.

➂ Adjust the angle of the Launcher to zero degrees so it will shoot horizontally.

Procedure

➀ In front of the class, measure the initial height of the ball at muzzle level.

➁ Calculate the horizontal and vertical positions of the ball each 1/10 second until it hits the floor.

0.1

0.2

0.3

0.4

0.5

t (sec)

x = v

t (cm)

y = y

- (

/2)gt

(cm)

x = v