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Grade 12th passMechanics

A particle of mass m moving in a circle of radius r with centripetal acceleration of kt2 where k is constant, then net acceleration when speed of particle is v is

Profile image of Pawan joshi
7 Years agoGrade 12th pass
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Profile image of Askiitians Tutor Team
ApprovedApproved Tutor Answer1 Year ago

To determine the net acceleration of a particle moving in a circle with a given centripetal acceleration, we need to consider both the centripetal acceleration and any tangential acceleration that may be present. In this case, the centripetal acceleration is defined as \( kt^2 \), where \( k \) is a constant and \( t \) is time. Let's break this down step by step.

Centripetal Acceleration Explained

Centripetal acceleration (\( a_c \)) is the acceleration directed towards the center of the circular path that keeps the particle moving in a circle. It can be expressed mathematically as:

  • Formula: \( a_c = \frac{v^2}{r} \)

Here, \( v \) is the speed of the particle, and \( r \) is the radius of the circular path. In your case, we have \( a_c = kt^2 \), which means:

  • Equating: \( \frac{v^2}{r} = kt^2 \)

Tangential Acceleration Consideration

Next, we need to consider the tangential acceleration (\( a_t \)). This type of acceleration occurs when there is a change in the speed of the particle along the circular path. If the speed \( v \) is changing with respect to time, we can express tangential acceleration as:

  • Formula: \( a_t = \frac{dv}{dt} \)

In this scenario, if the speed \( v \) is constant, then \( a_t = 0 \). However, if \( v \) is changing, we would need to know how \( v \) varies with time to calculate \( a_t \).

Calculating Net Acceleration

The net acceleration (\( a_{net} \)) of the particle is the vector sum of the centripetal and tangential accelerations. Since these two components are perpendicular to each other, we can use the Pythagorean theorem to find the magnitude of the net acceleration:

  • Formula: \( a_{net} = \sqrt{a_c^2 + a_t^2} \)

Substituting the expressions we have:

  • Net Acceleration: \( a_{net} = \sqrt{(kt^2)^2 + a_t^2} \)

Final Expression

Thus, if we assume that the tangential acceleration is zero (meaning the speed \( v \) is constant), the net acceleration simplifies to:

  • Result: \( a_{net} = kt^2 \)

If \( v \) is changing, you would need to substitute the appropriate value for \( a_t \) based on how \( v \) varies with time. In summary, the net acceleration of the particle depends on both the centripetal acceleration and any tangential acceleration present, and can be calculated using the formulas provided.