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What does the rate of change of height represent?
What does the rate of change of height represent?
What is the derivative of velocity with respect to displacement?
What is the derivative of velocity with respect to displacement?
How can you find the maximum height reached by an object?
How can you find the maximum height reached by an object?
What is the unit of velocity when it is represented as ds/dt?
What is the unit of velocity when it is represented as ds/dt?
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What does the derivative of displacement with respect to time represent?
What does the derivative of displacement with respect to time represent?
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How can you find the velocity of an object given its displacement function?
How can you find the velocity of an object given its displacement function?
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What is the relationship between velocity and acceleration?
What is the relationship between velocity and acceleration?
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What is the purpose of the derivative dv/ds?
What is the purpose of the derivative dv/ds?
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What is the height of the toy rocket after 3 seconds?
What is the height of the toy rocket after 3 seconds?
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What is the rate of change of F with respect to x in the formula F = 600/x^2?
What is the rate of change of F with respect to x in the formula F = 600/x^2?
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What is the velocity of the particle after t seconds, given the acceleration a = 2t i^→ + t^2 j^→?
What is the velocity of the particle after t seconds, given the acceleration a = 2t i^→ + t^2 j^→?
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What is the displacement of the particle after 12 seconds, given the acceleration a = 2t i^→ + t^2 j^→?
What is the displacement of the particle after 12 seconds, given the acceleration a = 2t i^→ + t^2 j^→?
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What is the length of the string when it exerts a force of magnitude 30N, given the elastic constant k = 5 N/m and natural length l_o = 3m?
What is the length of the string when it exerts a force of magnitude 30N, given the elastic constant k = 5 N/m and natural length l_o = 3m?
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How far will the string stretch when a 5kg mass is attached to the end of it, given the elastic constant k = 120 N/m and natural length l_o = 1.5m?
How far will the string stretch when a 5kg mass is attached to the end of it, given the elastic constant k = 120 N/m and natural length l_o = 1.5m?
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What is the work done in extending the spring by 0.1m, given the natural length 0.3m and elastic constant 6N/m?
What is the work done in extending the spring by 0.1m, given the natural length 0.3m and elastic constant 6N/m?
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What is the work done in extending the spring from 0.1m to 0.2m, given the natural length 0.3m and elastic constant 6N/m?
What is the work done in extending the spring from 0.1m to 0.2m, given the natural length 0.3m and elastic constant 6N/m?
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What is the maximum height of an object, given the function H(t) = 6t - t^2?
What is the maximum height of an object, given the function H(t) = 6t - t^2?
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What is the derivative of acceleration used to derive the SUVAT equations?
What is the derivative of acceleration used to derive the SUVAT equations?
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What is the formula for the work done by a variable force?
What is the formula for the work done by a variable force?
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What is the correct equation for the velocity of an object under constant acceleration?
What is the correct equation for the velocity of an object under constant acceleration?
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What is the correct equation for the displacement of an object under constant acceleration?
What is the correct equation for the displacement of an object under constant acceleration?
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What is the correct equation for the acceleration of an object under variable acceleration?
What is the correct equation for the acceleration of an object under variable acceleration?
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What is the concept of proportionality?
What is the concept of proportionality?
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What is the correct equation for the retardation of a car experiencing a retardation proportional to the square of its speed?
What is the correct equation for the retardation of a car experiencing a retardation proportional to the square of its speed?
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What is the correct approach to solve a problem involving variable forces?
What is the correct approach to solve a problem involving variable forces?
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What is the correct equation for the velocity of an object under the influence of gravity and air resistance?
What is the correct equation for the velocity of an object under the influence of gravity and air resistance?
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What is the correct approach to solve a problem involving proportional acceleration?
What is the correct approach to solve a problem involving proportional acceleration?
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What is the correct equation for the displacement of an object under variable acceleration?
What is the correct equation for the displacement of an object under variable acceleration?
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What is the formula for power in terms of force and velocity?
What is the formula for power in terms of force and velocity?
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If an object starts from rest, what is the initial velocity?
If an object starts from rest, what is the initial velocity?
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What is the differential equation for the amount of a radioactive substance A(t) in terms of time t?
What is the differential equation for the amount of a radioactive substance A(t) in terms of time t?
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What is the general solution to the differential equation dC/dt = -kC, where C(t) is the concentration of a drug at time t?
What is the general solution to the differential equation dC/dt = -kC, where C(t) is the concentration of a drug at time t?
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What is the differential equation for the temperature of a cup of coffee T(t) in terms of time t, according to Newton's Law of Cooling?
What is the differential equation for the temperature of a cup of coffee T(t) in terms of time t, according to Newton's Law of Cooling?
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What is the general solution to the differential equation dT/dt = -k(T - T_env), where T0 is the initial temperature of the coffee?
What is the general solution to the differential equation dT/dt = -k(T - T_env), where T0 is the initial temperature of the coffee?
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What is the rate at which a chemical concentration C(t) changes in a solution, according to the differential equation?
What is the rate at which a chemical concentration C(t) changes in a solution, according to the differential equation?
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What is the general solution to the differential equation dC/dt = -k(C - C_desired), where C_desired is the desired concentration?
What is the general solution to the differential equation dC/dt = -k(C - C_desired), where C_desired is the desired concentration?
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Study Notes
Rates of Change
- When a question mentions "rate of change of ______", we can model it as a derivative.
- The rate of change of time will always be at the bottom of the derivative, unless stated otherwise in the question.
Calculus in Kinematics
- Velocity (v) is the derivative of displacement (s) with respect to time (t):
ds/dt = v
- Acceleration (a) is the derivative of velocity with respect to time:
dv/dt = a
- We can integrate velocity to find displacement and differentiate acceleration to find velocity.
Worked Examples in Kinematics
- Example 1: Finding the height, speed, and maximum height of a ball thrown vertically upwards using derivatives.
- Example 2: Finding the rate of change of the force of attraction between two objects using derivatives.
Vector Calculus
- To differentiate or integrate a vector, do it separately for the i and j components.
- Worked Example 1: Finding the velocity and displacement of a particle with acceleration
a = 2t i + t^2 j
.
Hookes Law
- Hookes Law states that the restoring force (F) is proportional to the extension (l-lo) of a spring or string:
F = -k(l-lo)
- The "minus" sign indicates that the restoring force is in the opposite direction.
- Worked Examples 1 and 2: Finding the length of a string when it exerts a certain force using Hookes Law.
Work Done by a Variable Force
- The formula for work done is
W = ∫F dx
. - Worked Example 1: Finding the work done in extending a spring by a certain distance using Hookes Law.
Deriving Equations of Motion
- We can derive the equations of motion using calculus, including:
-
v = u + at
(velocity-time equation) -
s = ut + 1/2 at^2
(position-time equation) -
v^2 = u^2 + 2as
(velocity-position equation)
-
- Derivations involve setting up equations using the derivatives
dv/dt = a
andv dv/ds = a
.
Variable Acceleration
- If acceleration is linked to velocity and time, use the derivative
dv/dt = a
. - If acceleration is linked to velocity and displacement, use the derivative
v dv/ds = a
. - Worked Example 1: Finding the time taken for the speed of a particle to increase from 25 m/s to 75 m/s using a differential equation.
Proportional Acceleration
- There are two types of proportionality: direct and inverse.
- Direct proportionality:
y = kx
, where k is the constant of proportionality. - Inverse proportionality:
y = k/x
, where k is the constant of proportionality. - Worked Example 1: Finding the time taken for a car to travel a certain distance using a proportionality.
Non-Mechanics Calculus
- These questions involve solving differential equations, such as:
-
dA/dt = -kA
( radioactive substance decay) -
dC/dt = -kC
(concentration of a drug in the bloodstream) -
dT/dt = -k(T - T_env)
(Newton's Law of Cooling)
-
- Worked Examples 1 and 2: Solving these differential equations to find the general solutions.
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Description
Learn how to model rates of change as derivatives, understanding the concept of dh/dt and its application in kinematics.