The relationship between speed of a wave w, frequency f and wavelength
is
For the wave of our problem,
and f=60 Hz, so its speed is
Answer:
1. 10.0 J
2. 0.742 m/s
3. 0.494 m/s
4. 0.0249 m
Explanation:
(1/4) The elastic energy in a spring is:
EE = ½ k x²
EE = ½ (502 N/m) (0.2 m)²
EE ≈ 10.0 J
(2/4) The energy in the spring is converted to kinetic energy in the block and work by friction.
EE = KE + W
EE = ½ m v² + Fd
10.0 J = ½ (8 kg) v² + (8 kg × 9.8 m/s² × 0.5) (0.2 m)
v ≈ 0.742 m/s
(3/4) Momentum is conserved.
Momentum before = momentum after
(8 kg) (0.742 m/s) = (8 kg + 4 kg) v
v ≈ 0.494 m/s
(4/4) The kinetic energy of the blocks is converted to work by friction.
KE = W
½ m v² = Fd
½ (8 kg + 4 kg) (0.494 m/s)² = ((8 kg + 4 kg) × 9.8 m/s² × 0.5) d
d ≈ 0.0249 m
To solve the problem it is necessary to apply the conservation equations of the moment.
The conservation equation of the moment is defined as,
Where,
Mass of Bird
Mass of Insect
Velocity Bird before swallowing
Velocity of insect
final velocity (both)
Replacing with our values we have,
Therefore the bird's speed immediately after swallowing is 7.83m/s