Answer:
k = 5178.8 N/m
Explanation:
As we know that spring mass system will oscillate at angular frequency given as

now we have

now the maximum acceleration of the spring block system is at its maximum compression state which is given as

here A= maximum compression of the spring
so here in order to find maximum compression of the spring we will use energy conservation as we know that initial total kinetic energy of the car will convert into spring potential energy

here we know that
v = 85 km/h

now we have


now from above equation of acceleration we have



Answer:D) His Facial expressions when they spend time together
Explanation:
Eva's should carefully observe the normal verbal signs by her lover because facial expression gives the hint to listener or viewer that one is interested towards other.
Some common facial Expression are
- Smiling Eyes:While smiling is, of course, an important expression when we speak, attempting to keep a constant smile could make you look more like a trained sociopath than a happy, enthusiastic presenter. These enables other person to feel the good vibes out of you and left a positive impact of your presence.
- Nod on: It is important to express interest in the feedback of your audience. No one likes an identity-centered snob. One way to show that you're actually engaged in the comments and questions they pose is by nodding while you're listening. Moving your head a little wider will help to express your attention as well.