Calculate your maximum heart rate and then measure your heard rate While you areperforming each of three physical activities. Which activities meeting the intensityguideline to help improve your cardiovascular endurance? Based on your goals, howmany days per week and for how long should you perform the activity?a. Cross Country practice, Hiking, Basketball drillsb. Cross country practice is the only one to meet the guidelines. I think I would haveto do it at least 4 times a week for 30 minutes to see how far I can during that time

c) up is the direction the magnetic force is acting on the charge.

i think the answer is a and b

i wish you luck

speed of light in vacuum is 300,000 km/s

speed of light in other mediums is given by the expression v = c/n, where c is the speed of light in vacuum and n is the refractive index of medium.

for the first medium v = 200,000 km/s

  so, refractive index of medium = 300000/200000 = 1.5

    1.5 refractive index is usually for glass. so first medium is glass.

for the second medium v = 250,00 km/s

so, refractive index of medium = 300000/250000 = 1.2

    1.2 refractive index is usually for water. so second medium is water.

for the third medium v = 0 km/s

so, refractive index of medium = 300000/0 = ∞

    ∞ refractive index is usually for opaque mediums. so third medium is opaque medium.