A 2-kg toy car sits at the highest point of a 13-meter-high hill. The car is gen

Question

A 2-kg toy car sits at the highest point of a 13-meter-high hill. The car is gently pushed forward until it begins to roll down the slope. Assuming the car coasts freely, without any friction or air resistance, how much kinetic energy (KE) and potential energy (PE) will it have at each of the indicated points? Complete the diagram by placing the correct label in each bin. Use for the acceleration due to gravity, g 10 m/s2. Note, the diagram below is not drawn to scale. 14 J 520 J 140 J 26 J 220 J 4 J260 J40 J120 J0J PE = KE = KE- 13 m 7 m KE=

Explanation / Answer

PE = mass*gravity*height

KE=1/2 mass*velocity^2

1)

at hight 13 m

PE= 13*9.81*2=255.06

KE=0 (initially toy car is in rest)

(2)

at the height of 2m

E (at height 13m) = E(at hight 2m) (energy conservation)

255.06 = KE +PE

PE = m*g*h = 2*2*9.8 = 39.24 J

255.06 = KE + 39.24

K E = 215.06 J

3)

at the height 7m

PE = 6*2*9.81= 117.72 J.

KE=255.06 -117.72=137.33 J

4) at the ground

PE= 0*2*9.81=0 J

which means that KE= 255.06 J

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

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