Complete this paragraph regarding dangers from the Sun. X-rays and UV rays from the Sun can disrupt 1)_ radio communication from ground-based radio towers. 2) _ may also be affected by solar particles that can damage equipment. Humans in 3)_ are also susceptible to radiation damage from the Sun. Solar activity can also cause 4)_ that can damage electrical transformers and power stations.

1)
A. Ultra high-radiation
B. High-frequency
C. Low-frequency

2)
A. Aircraft
B. Sea Vessels
C. Satelites

3)
A. Spacecraft
B. Airplanes
C. High Mountains

4)
A. Thermal Heating
B. Geomagnetic Storms
C. Electrical storms

If you need further clarification check the attached image. Thanks for the help.

Describe uniform velocity and variable velocity in short

The frequency of vibrations of a vibrating violin string is given by f = 1 2l t ρ where l is the length of the string, t is its tension, and ρ is its linear density.† (a) find the rate of change of the frequency with respect to the following. (i) the length (when t and ρ are constant) (ii) the tension (when l and ρ are constant) (iii) the linear density (when l and t are constant) (b) the pitch of a note (how high or low the note sounds) is determined by the frequency f. (the higher the frequency, the higher the pitch.) use the signs of the derivatives in part (a) to determine what happens to the pitch of a note for the following. (i) when the effective length of a string is decreased by placing a finger on the string so a shorter portion of the string vibrates df dl 0 and l is ⇒ f is ⇒ (ii) when the tension is increased by turning a tuning peg df dt 0 and t is ⇒ f is ⇒ (iii) when the linear density is increased by switching to another string df dρ 0 and ρ is ⇒ f is ⇒

A5 foot by 5 foot box culvert is buried 6 feet beneath the surface of the ground. a crosssection of this very long culvert (into and out of the page) is illustrated below. assume that the soil in which the culvert is buried has the following properties: jt = 120 pcf, w = 12%, ko = 0.50, ka = 0.33, and kp = 3.00. calculate the total horizontal force per unit length of culvert (fh) felt on one of the vertical faces of the culvert.