Question

To protect their young in the nest, peregrine falcons will fly into birds of prey (such as ravens) at high speed. In one such episode, a 600-g falcon flying at 20.0 m/s hit a 1.50-kg raven flying at 9.0 m/s. The falcon hit the raven at right angles to its original path and bounced back at 5.0 m/s. (These figures were estimated by the author as he watched this attack occur in northern New Mexico.) (a) By what angle did the falcon change the raven’s direction of motion? (b) What was the raven’s speed right after the collision?

Answer 1

Answer:

Part a)

$\theta = 48 degree$

Part b)

$v = 13.45 m/s$

Explanation:

Part a)

mass of the Falcon bird is given as

$m = 600 g$

initial speed of the bird is

$v_i = 20 m/s$

final speed of the bird is given as

$v_f = 5 m/s$ (opposite direction)

So here the impulse given by falcon bird is given as

$I = m(v_f - v_i)$

$I = 0.600(20 + 5)$

$I = 15 kg m/s$

now the final momentum of Raven bird in perpendicular direction is given as

$I = mv_y$

$15 = 1.50 v_y$

$v_y = 10 m/s$

now the change in the angle of the raven bird is given as

$tan\theta = \frac{v_y}{v_x}$

$tan\theta = \frac{10}{9}$

$\theta = 48 degree$

Part b)

Final speed of the raven bird is given as

$v^2 = v_x^2 + v_y^2$

$v^2 = 9^2 + 10^2$

$v = 13.45 m/s$