1.Air resistance is present on a ball launched horizontally out a window, striki

Question

1.Air resistance is present on a ball launched horizontally out a window, striking the ground ten seconds later. What will the air resistance do to the following system consisting of the spring, ball, Earth, air, and ground?

Reduce final impact velocity.

Decrease the thermal energy of the system.

Heat up the air a very small amount.

Reduce final energy of system.

Reduce the horizontal length traveled compared to no air resistance.

2. A pole vaulter (mass = 75kg) sprints down the track and hits a speed of 10m/s at the instant she plants the pole in the "box" (->Ek). The vaulter expends 4000J (=Ec) of energy sprinting down the track. The pole bends 4m and has a spring constant of 400N/m (->Eel). The vaulter achieve a maximum height of 4.2m (->E

Reduce final impact velocity.

Decrease the thermal energy of the system.

Heat up the air a very small amount.

Reduce final energy of system.

Reduce the horizontal length traveled compared to no air resistance.

Explanation / Answer

Option - e, Reduce the horizontal length traveled compared to no air resistance

Since air will reduce horizontal velocity of ball,

******************************************

Initial K.E = 1/2 *75 *10^2

Ek = 3750 J

Ec = 4000 J

Energy in pole = 1/2 *k*x^2

Eel = 3200 J

Eg = 3087 J

Et = 3038 J

so, Ec > Ek > Eel > Eg > Et

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.