Precalculus

Can someone check my answers please? Thank you :)

30. What is Earth's rotational speed at (a) Bangor, Maine (latitude 45 degrees N) and (b) Rio de Janeiro, Brazil (latitude 23 degrees S)? (It's given in the problem also that Earth's rotational speed at the equator is about 1,038 mph and Earth's radius is 3,963 miles.)

(a) 734 mph
(b) 899 mph

Are these answers correct?

  1. 👍 0
  2. 👎 0
  3. 👁 236
asked by Emily
  1. I would call the speeds tangential speed, since it is a speed measured along the tangent. A rotational speed is measured in radians/second, or degrees per minute, etc.

    Assuming the earth is a perfect sphere, the tangential speed at latitude θ (north or south) is given by multiplying the speed at the equator (1038 mph) by the cosine of the latitude.
    (a) 1038*cos(45)=734 mph
    (b) 1038*cos(23)=952 mph.
    Your answer of 899 was probably due to an error of the angle and corresponds to a latitude of 30 degrees south.

    1. 👍 0
    2. 👎 0

Respond to this Question

First Name

Your Response

Similar Questions

  1. Physics

    Take into account the Earth's rotational speed (1 rev/day) and determine the necessary speed, with respect to the Earth, for a rocket to escape if fired from the Earth at the equator in a direction a) eastward; b) westward; c)

    asked by Steve on March 19, 2008
  2. Physics

    Take into account the Earth's rotational speed (1 rev/day) and determine the necessary speed, with respect to the Earth, for a rocket to escape if fired from the Earth at the equator in a direction a) eastward; b) westward; c)

    asked by Steve on March 19, 2008
  3. physics

    A heavy flywheel rotating on its central axis is slowing down because of friction on its bearings. At the end of the first minute of slowing, its rotational speed is 0.90 of its intial rotational speed of 250 rev/min. Assuming a

    asked by laura on December 4, 2006
  4. Physics- drwls please help

    (a) Calculate the kinetic energy that the earth has because of its rotation about its own axis. Assume that the earth is a uniform sphere and that its path around the sun is circular. For comparison, the total energy used in the

    asked by Jim on March 28, 2007
  5. physics

    A geosynchronous Earth satellite is one that has an orbital period equal to the rotational period of the Earth. Such orbits are useful for communication and weather observation because the satellite remains above the same point on

    asked by Anonymous on June 8, 2014
  6. physics

    Find the rotational kinetic energy of the earth about the sun due to its orbit about the sun. The mass of the earth M is 6 x 1024 kg, the orbital radius r is 1.5 x 1011 m and the rotational period T is 1 year. Treat the earth as a

    asked by Qay on December 3, 2010
  7. physics

    Find the rotational kinetic energy of the earth about the sun due to its orbit about the sun. The mass of the earth M is 6 x 1024 kg, the orbital radius r is 1.5 x 1011 m and the rotational period T is 1 year. Treat the earth as a

    asked by Maa on December 4, 2010
  8. physics

    A trapeze artist sailing through the air rotates with a rotational speed of 0.9·rev/s. If she contracts to reduce her rotational inertia to one sixth of what it was, what will her new rotational speed be? _____ rev/s? Can she

    asked by wally on February 6, 2013
  9. Physics

    Take into account the Earth's rotational speed (1 rev/day) and use 5 significant figures. (a) Determine the necessary speed, with respect to Earth, for a rocket to escape if fired from the Earth at the equator in a direction

    asked by Anonymous on February 26, 2014
  10. science

    The true speed of a moving car on the Earth, if you want to be very precise, would be the speed of the car with respect to the ground Is this true? yeah it is true yeah it is true The true speed of a moving car on the Earth, if

    asked by Haley on May 10, 2007

More Similar Questions