Question

1. calculate the kinetic energy of baseball - sized hail (0.200 kg) given it will fall towards earth with an average velocity of 39.3 m/s.

a. 309 j
b. 154 j
c. 7.86 j
d. 3.93 j

1. calculate the momentum of baseball - sized hail (0.200 kg) as it falls towards earth.

a. 5.09 kg·m/s
b. 7.86 kg·m/s
c. 197 kg·m/s
d. 7860 kg·m/s

1. baseball - sized hail is classified as severe weather due to its potential to cause significant damage. upon impact it can shatter windows, dent roofs and siding on homes, and flatten crops. should hail of baseball - size hit the hood of a vehicle, severe deformation of the metal will occur. this is an example of an (elastic / inelastic) collision because kinetic energy (is / is not) conserved.
2. calculate the wavelength of a wave as it travels given its velocity is 6000 m/s and it has a frequency of 10 hz.

a. 0.0017 m
b. 0.1 m
c. 600 m
d. 60,000 m

1. calculate the frequency of a wave that has a period of 0.2 seconds.

a. 2 hz
b. 5 hz
c. 20 hz
d. 50 hz

Explanation:

Step1: Use kinetic energy formula

$KE = \frac{1}{2}mv^2$ where $m=0.200 \text{ kg}$, $v=39.3 \text{ m/s}$
$KE = \frac{1}{2} \times 0.200 \times (39.3)^2 = 0.1 \times 1544.49 = 154.449 \approx 154 \text{ J}$

Step2: Use momentum formula

$p = mv$ where $m=0.200 \text{ kg}$, $v=39.3 \text{ m/s}$
$p =0.200 \times39.3 =7.86 \text{ kg·m/s}$

Step3: Identify collision type

The hail deforms the car hood, kinetic energy is lost in the deformation, so it is an inelastic collision where kinetic energy is not conserved.

Step4: Use wave velocity formula

$\lambda = \frac{v}{f}$ where $v=6000 \text{ m/s}$, $f=10 \text{ Hz}$
$\lambda = \frac{6000}{10}=600 \text{ m}$

Step5: Relate frequency and period

$f=\frac{1}{T}$ where $T=0.2 \text{ s}$
$f=\frac{1}{0.2}=5 \text{ Hz}$

Answer:

1. Question7: b. 154 J
2. Question8: b. 7.86 kg·m/s
3. Question9: inelastic; is not
4. Question10: c. 600 m
5. Question11: b. 5 Hz