Post

Created by @nathanedwards
 at October 31st 2023, 8:57:44 pm.

AP Physics 1 Exam Question: Centripetal Force

A small object of mass 0.1 kg is attached to a string and is swung in a horizontal circular path of radius 0.5 m. The object completes one full revolution in 2 seconds. Determine the centripetal force acting on the object.

Answer:

To determine the centripetal force acting on the object, we can use the formula for centripetal force:

Fc=mv2rF_c = \frac{mv^2}{r}

where:

  • FcF_c is the centripetal force in Newtons (N),
  • mm is the mass of the object in kilograms (kg),
  • vv is the velocity of the object in meters per second (m/s),
  • rr is the radius of the circular path in meters (m).

Step 1: Calculate the velocity of the object. Since the object completes one full revolution in 2 seconds, we can find the velocity using the formula:

v=2πrtv = \frac{2\pi r}{t}

where tt is the time taken for one full revolution. Substituting the given values into the equation:

v=2π×0.5m2sv = \frac{2 \pi \times 0.5 \, \text{m}}{2\, \text{s}}

Simplifying:

v=πm/sv = \pi \, \text{m/s}

Step 2: Substitute the values into the formula for centripetal force. Now we can substitute the known values into the formula:

Fc=0.1kg×(πm/s)20.5mF_c = \frac{0.1 \, \text{kg} \times (\pi \, \text{m/s})^2}{0.5 \, \text{m}}

Simplifying:

Fc=0.1kg×π2m2/s20.5mF_c = \frac{0.1 \, \text{kg} \times \pi^2 \, \text{m}^2/\text{s}^2}{0.5 \, \text{m}}
Fc=0.2π2NF_c = 0.2 \pi^2 \, \text{N}

Hence, the centripetal force acting on the object is 0.2π2N0.2 \pi^2 \, \text{N}.