1. Which of the following regarding a collision is/are true? a. If you triple your speed your force of impact will be three times greater b. Speed has little effect on impact forces c. If you double your speed, the energy dissipated in a crash is four times greater d. If you double your speed, the energy dissipated in a crash is two times greater

c. If you double your speed, the energy dissipated in a crash is four times greater.

Explanation:

Given:

Impulse, P = force, f × time, t

= mass, m × velocity, v

Energy = kinetic energy, E = 1/2 × m × v^2

At v2 = 2v1

E1 = 1/2 × m × v1^2

= (m × v1^2)/2

E2 = 1/2 × m × (2v1^2)

= 1/2 × m × 4v1^2

= m × 2v1^2

(2 × E1)/v1^2 = E2/2v1^2

E1 = E2/4

E2 = 4 × E1

attach the statements so i can answer : )

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.