Here is another lab that I need help with.... Lab 5: Rocket THEORY An accelerate

Question

Here is another lab that I need help with....

Lab 5: Rocket

THEORY
An accelerated object is one whose velocity is changing. For a straight line motion we can calculate the final speed (v) if we know the initial speed (v0), acceleration (a) and time (t) using the formula
v = v0 + at

When an object is thrown upward the effect of the downward acceleration of gravity is at first to reduce the objects upward speed. The upward speed decreases steadily until finally it is zero. The object is then at the top (peak) on its path, when the object is at rest for an instant.

For this case
final speed v = 0 and
acceleration a = -g = -9.8 m/s2 because it is a decelerated motion.

The object then begins to fall at increasing speed. Interestingly enough, something thrown upward at a certain speed will return to its starting point with the same speed (if we consider the air friction negligible), although the object is now moving in the opposite direction.

The distance under constant acceleration can be calculated using the following formula:

d = v0t + ½ at2

METHOD
We will measure the time the rocket is in an upward motion, from the time it leaves the ground, to its highest point (peak). We will also observe and measure the highest distance (peak) from the ground that the rocket reaches.

We will determine the initial speed of the rocket using the speed formula.

v0 = __________

(Hint: use the final speed and acceleration values stated above.)


MATERIALS NEEDED
Camera film canister with snap on lid, toilet paper roll, construction paper, scissors, scotch tape, Alka-Seltzer tablets (or generics), water, eye protection (glasses, sunglasses), stop watch and ruler.

PROCEDURE
• Cut down the side of the toilet paper roll (also shorten the length).
• Insert film canister at one end, having lid stick out about 1/8”.
• Tape one edge of the toilet paper roll onto the film canister. Roll the toilet paper roll around the canister and tape tightly into place.
• Cut a circle out of the construction paper, cutting a pie shaped wedge out of the circle. (Different sizes may affect the launch of the rocket)
• Roll the construction paper into a cone shape and tape onto the other end of the toilet paper tube.



GO OUTSIDE for the remainder
• Put on eye protection (glasses, goggles, sunglasses).
• Turn the rocket upside down.
• Remove lid from the canister.
• Fill ¼ full with water.
• Drop in tablet of Alka-Seltzer.
• IMMEDIATELY replace lid and set upright on ground.
• MOVE AWAY and WATCH the rocket in the air.


With a stop watch, measure the time the rocket is in an upward motion, from the time it leaves the ground, to its highest point (peak) and record in the table. Observe and measure the highest distance (peak) from the ground that the rocket reaches and record in the table. Calculate the initial speed.

Time (peak)
in s Initial speed
in m/s Distance (peak)
in m

1 Alka-Seltzer


1 Alka-Seltzer


2 Alka-Seltzer


4 Alka-Seltzer



Table 1




DISCUSSION
1. Did you find that the more Alka-Seltzer in the canister, the higher the rocket went? Why do you think this happened? ____________________________________________
________________________________________________________________________________________________________________________________________________________________________________________________________________________


2. Give reasons for errors in your measurements. ________________________________
________________________________________________________________________________________________________________________________________________________________________________________________________________________

Explanation / Answer

let initial velocity of the rocket is v0m/s at maximum hieght final velocity will be zero v =0m/s let maximum height is =h meters the time taken to reach maximum hieght is = t sec from the equation of the motion h =ut+1/2gt2...........(1) due to upward motion acceleration due to gravity is '-g' m/s2 from equation (1) from equation (1) h=v0t-gt2 initial velocity v0=(h+gt2)/t initial velocity v0=(h+gt2)/t

Related Questions

Navigate

• Browse (All)
• Browse H
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.