How to Calculate Contact Force
- 1). Determine the total mass of the system by combining the masses of the individual bodies. For example, if the system consists of two blocks with masses of 4 kilograms (kg) and 8 kg, respectively, then the total mass is 12 kg.
- 2). Calculate the acceleration of the system, given the total force and the total mass of the system--for example, the two bodies are being pushed by a force of 30 Newtons (N). The acceleration can be calculated by dividing the force of 30 N by the combined mass of the bodies, which is 12 kg. Completing this calculation yields 2.5 meters per second square (m/s^2) as the acceleration.
- 3). Multiply the acceleration of the bodies by the mass of the larger body to find the contact force. In this example, multiplying 2.5 m/s^2 by 8 kg gives 20 N. This is the contact force between the two blocks.
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