Centripetal force help anyone? I dont need a website i just want you to type out how you figured it out?

Question

Centripetal force help anyone? I dont need a website i just want you to type out how you figured it out and the answer so here goes:

1.What is the centripetal force acting on an 1.5kg object moving in a circular path wiht a centripetal force of 18 m/s2?

2.A 100 g mass is attched to a string 75sm long and swings in a horizontal circle the mass goes around its path once ever .80 sec.
What is the centripetal acceleration of the object and calc the tension of the string

3. It takes a 900 kg racing car 12.3 seconds to travel at a uniform speed around a circular racetrack of 90 meteter radius
what is the centripetal acceleration of the car?
How much centripetal force is acting on the car?
What provides the centripetal force?

Answer 1

1) I think your 2nd c.f. should say c. acceleration; that's the units you're using------ the c force of a mass m with acceleration a is f = ma, so youhave 1.5 kg*18 m/s² = 27 N

2) First find the velocity: v = d/t = 2πr/t = 2π*.75m/.8sec = 5.89 m/s
Then, acceleration: a = v²/r = 5.89²/.75 = 46.256 m/s²
Then, the tension: T = ma = .1kg*26.256m/s² = 2.626 N

3) v = 2πr/t = 2π*90/12.3sec = 45.974m/s
a = v²/r = 45.97²/90 = 23.485 m/s²
F = ma = 900*23.485 = 21,136.5 N
The lateral friction of the tires on the track

Answer 2

In order to keep an object moving in a circle, whatever is holding it must counteract the centrifugal force from its motion. The centrifugal force is directed radially outward, so the centripetal force is directed radially inward and is equal in magnitude to the centrifugal force. In part 1 of your question I assume the statement should be "with a centripetal acceleration of 18m/sec^2". Force is mass times acceleration: you have the mass (1.5kg) and the acclereration (18m/sec^2); you figure the force.

Centripetal acceleration is w^2*r, where w = angular velocity in radians/sec. The rotation is once per .8 sec, and one rotation is 2π radians, so the angular velocity is 2π/.8 radian/sec. You can now compute the acceleration. The tension in the string it the centripetal force which counteracts the centrifugal force. The centrifugal force is the mass times the centripetal acceleration.

The last part is the same as the second part with different numbers. The angular velocity w is one revolution in 12.3 seconds, and one revolution is 2π radians. The rest you get the same way as in part 2. What do you think provides the centripetal force? Hint: what would happen to the car if the track were covered with oil?

Answer 3

Alright for the first one I think you ment that 18 m/s/s is acceleration and not the force right? Ok if the acceleration is 18 m/s/s then the centripetal force acting on the aboject is 27 Newtons

2) if 75 is centimeter then it should be 'cm' not 'sm'
Centripetal acceleration= 46.26 m/s/s
Centripetal force = 4.62N

3) centripeteal acceleration = 23.48 m/s/s
centripetal force = 21131.409N
friction between tire and road provides the centripetal force