Centripetal force calculation. Illustration of a racing car banking around a race track. The labels show the calculation of the centripetal force acting on the car and driver. The car is on the bank at an angle of theta. The weight (mg) acts downwards, equal to mass (m) multiplied by gravity (g). The reaction force acting perpendicular to the race track can be resolved by trigonometry into two components. The vertical component is the reaction force multiplied by the cosine of the angle theta. This vertical component is equal to the weight. The horizontal component is the reaction force multiplied by the sine of the angle theta.