Physics-rocket activity-calculating drag..

Rocket activity

Calculating drag.

Click for definition of terms

C Determination of Average Drag Between B and C
Accepting that H + h is the more accurate value for the height reached by the rocket we will use it to work backwards and make an estimate of air resistance(drag) between B and C.

• Subtract your value of x_AB from H + h to get a more accurate value of x_BC.

• Use your value of v_B (from near top of p.2)and your improved value of x_BC to determine the average acceleration between B and C.

• Calculate the average net force on the rocket between B and C and use this to calculate the average drag between B and C

D Determination of More Accurate Value of v_B and x_AB

This will be done by repeating the calculations on pp 1 and 2 with a value for drag included.
• Note that for the motion from A to B speed increases from 0 to v_B , while for the motion from B to C the speed changes from v_B to 0. It is therefore a reasonable assumption that the average drag from A to B is the same as that from B to C.

•Calculate the average resultant force on the rocket as it moves from A to B and hence find a value for its average acceleration

• Use your calculated value of t_AB from p 1, together with this improved value of the acceleration to find vB and x_AB. Hint

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Maximum height of rocket = H + h
Mass of rocket before firing = m_i
Mass of rocket after fuel is exhausted = m_f
Time from A to C (stopwatch) = t_AC
Time from A to B = t_AB
Time from B to C = t_BC
Average drag from B to C = F_BC
Vertical component of AB = x_AB
Vertical component of BC = x_BC
Distance between observers = D
Sight angles of observers = X1 , X2
Speed of rocket at B = v_B

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Rocket activity Calculating drag.
Click for definition of terms C Determination of Average Drag Between B and C Accepting that H + h is the more accurate value for the height reached by the rocket we will use it to work backwards and make an estimate of air resistance(drag) between B and C.
• Subtract your value of x_AB from H + h to get a more accurate value of x_BC.
• Use your value of v_B (from near top of p.2)and your improved value of x_BC to determine the average acceleration between B and C.
• Calculate the average net force on the rocket between B and C and use this to calculate the average drag between B and C
D Determination of More Accurate Value of v_B and x_AB This will be done by repeating the calculations on pp 1 and 2 with a value for drag included. • Note that for the motion from A to B speed increases from 0 to v_B , while for the motion from B to C the speed changes from v_B to 0. It is therefore a reasonable assumption that the average drag from A to B is the same as that from B to C.
•Calculate the average resultant force on the rocket as it moves from A to B and hence find a value for its average acceleration
• Use your calculated value of t_AB from p 1, together with this improved value of the acceleration to find vB and x_AB. Hint Hide Maximum height of rocket = H + h Mass of rocket before firing = m_i Mass of rocket after fuel is exhausted = m_f Time from A to C (stopwatch) = t_AC Time from A to B = t_AB Time from B to C = t_BC Average drag from B to C = F_BC Vertical component of AB = x_AB Vertical component of BC = x_BC Distance between observers = D Sight angles of observers = X1 , X2 Speed of rocket at B = v_B Click to hide