Advertisements
Advertisements
Question
Earth can be thought of as a sphere of radius 6400 km. Any object (or a person) is performing circular motion around the axis of earth due to earth’s rotation (period 1 day). What is acceleration of object on the surface of the earth (at equator) towards its centre? what is it at latitude θ? How does these accelerations compare with g = 9.8 m/s2?
Advertisements
Solution
Radius of the earth (R) = 6400 km = 6.4 × 106 m
Time period (T) = 1 day = 24 × 60 × 60 s = 86400 s
Centripetal acceleration (ac) = `ω^2 R = R((2pi)/T)^2 = (4pi^2R)/T`
= `(4 xx (22/7)^2 xx 64 xx 10^6)/(24 xx 60 xx 60)^2`
= `(4 xx 484 xx 64 xx 10^6)/(49 xx (24 xx 3600)^2`
= 0.034 m/s2
At equator, latitude θ = 0°
∴ `a_c/g = 0.034/9.8 = 1/288`
APPEARS IN
RELATED QUESTIONS
State True or False
The earth moves around the sun with a uniform.
Name the force required for uniform circular motion. State its direction.
Answer the following question.
Show that the centripetal force on a particle undergoing uniform circular motion is -mrω2.
Solve the following problem.
A car moves in a circle at a constant speed of 50 m/s and completes one revolution in 40 s. Determine the magnitude of the acceleration of the car.
Which one of the following is most likely not a case of uniform circular motion?
If a particle moves with uniform speed then its tangential acceleration will be ______.
A particle goes round a circular path with uniform speed v. After describing half the circle, what is the change in its centripetal acceleration?
A small sphere is attached to a cord and rotates in a vertical circle about a point O. If the average speed of the sphere is increased, the cord is most likely to break at the orientation when the mass is at ____________.

Consider a simple pendulum of length 4 m. Its bob performs a circular motion in horizontal plane with its string making an angle 60° with the vertical. The Period of rotation of the bob is ____________.(Take g = 10 m/s2)
At any instant, the magnitude of the centripetal force on a particle of mass 'm' performing circular motion is given by (ω = angular velocity and v = linear velocity of the particle) ______.
A body moves in a uniform circular motion ______.
Which of the following is correct about uniform circular motion
- the direction of motion is continuously changed
- the direction of motion is not changed
- speed and direction both remain constant
- speed is constant but the direction is changing
In uniform motion, an object travels equal ______ in ______ interval of time.
It is possible to have objects moving with uniform velocity but non-uniform acceleration.
A rod PQ of mass M and length L is hinged at end P. The rod is kept horizontal by a massless string tied to point Q as shown in figure. When string is cut, the initial angular acceleration of the rod is ______.

A particle moves along a circle of radius r with constant tangential acceleration. If the velocity of the particle is v at the end of second revolution, after the revolution has started, then the tangential acceleration is ______.
Angular speed of hour hand of a clock in degree per second is ______.
A thin uniform circular disc of mass M and radius R is rotating in a horizontal plane about an axis passing through its centre and perpendicular to its plane with an angular velocity ω. Another disc of same dimensions, but of mass `1/4`M is placed gently on the first disc co-axially. The. angular velocity of the system is ______.
By applying Kepler's third law to the formula for centripetal force, Newton concluded that the force acting on a planet is:
