PHYSICS HELP

posted by .

The maximum lift force on a bat is proportional to the square of its flying speed v. For the hoary bat (Lasiurus cinereus), the magnitude of the lift force is given by
FL (0.021 N·s2/m2)v2
The bat can fly in a horizontal circle by "banking" its wings at an angle è, as shown in the figure below. In this situation, the magnitude of the vertical component of the lift force must equal the bat's weight. The horizontal component of the force provides the centripetal acceleration.

(a) What is the minimum speed that the bat can have if its mass is 0.037 kg?

(b) If the maximum speed of the bat is 11 m/s, what is the maximum banking angle that allows the bat to stay in a horizontal plane?


(c) What is the radius of the circle of its flight when the bat flies at its maximum speed?



then i was given,
lift*cosTheta=mg
lift*sinTheta=mv^2/r


on the first equation
.021v^2*cosTheta=mg
you know m, g, and v^2, solve for Theta

Then on the second, solve for r.


****BUT i don't know how i already know v^2?????

  • PHYSICS HELP -

    a) lift*sinTheta=mv^2/r and
    lift*cosTheta=mg

    well, it appears your comment is right, you are looking for min v given mass. Well, 0.021v^2*CosTheta=mg
    minimum V will be when CosTheta is max, or .021v^2=mg solve for v.

    b) now you know v, find r.
    first, find from the second equation .021v^2*cosTheta=mg solve for Theta.

    c) Put that in the first equation, find r.

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Physics

    The maximum lift force on a bat is proportional to the square of its flying speed v. For the hoary bat (Lasiurus cinereus), the magnitude of the lift force is given by FL (0.020 N·s2/m2)v2 The bat can fly in a horizontal circle by …
  2. Physics

    The maximum lift force on a bat is proportional to the square of its flying speed v. For the hoary bat (Lasiurus cinereus), the magnitude of the lift force is given by FL (0.021 N·s2/m2)v2 The bat can fly in a horizontal circle by …
  3. physics

    a baseball (m = 153 g) approaches a bat horizontally at a speed of 41.0 m/s (92 mi/h) and is hit straight back at a speed of 45.8 m/s (102 mi/h). If the ball is in contact with the bat for a time of 1.05 ms, what is the average force …
  4. physics

    A baseball (m = 151 g) approaches a bat horizontally at a speed of 39.8 m/s (89 mi/h) and is hit straight back at a speed of 45.7 m/s (102 mi/h). If the ball is in contact with the bat for a time of 1.05 ms, what is the average force …
  5. physics

    A baseball (m = 135 g) approaches a bat horizontally at a speed of 40.4 m/s (90 mi/h) and is hit straight back at a speed of 45.7 m/s (102 mi/h). If the ball is in contact with the bat for a time of 1.00 ms, what is the average force …
  6. Physics

    A baseball (m = 135 g) approaches a bat horizontally at a speed of 40.4 m/s (90 mi/h) and is hit straight back at a speed of 45.7 m/s (102 mi/h). If the ball is in contact with the bat for a time of 1.00 ms, what is the average force …
  7. physics

    A baseball (m = 148 g) approaches a bat horizontally at a speed of 43.8 m/s (98.0 mi/h) and is hit straight back at a speed of 48.4 m/s (108 mi/h). If the ball is in contact with the bat for a time of 1.08 ms, what is the average force …
  8. Physics

    A baseball (m = 149 g) approaches a bat horizontally at a speed of 42.2 m/s (94 mi/h) and is hit straight back at a speed of 48.1 m/s (108 mi/h). If the ball is in contact with the bat for a time of 1.10 ms, what is the average force …
  9. physics

    In a Little League baseball game, the 145 g ball enters the strike zone with a speed of 13.0 m/s. The batter hits the ball, and it leaves his bat with a speed of 21.0 m/s in exactly the opposite direction. 1. what is the magnitude …
  10. physics

    A pitcher throws a 0.141-kg baseball toward the batter so that it crosses home plate horizontally and has a speed of 42 m/s just before it makes contact with the bat. The batter then hits the ball straight back at the pitcher with …

More Similar Questions