While exploring a castle, Exena the Exerminator is spotied by a dragon who chase

Question

While exploring a castle, Exena the Exerminator is spotied by a dragon who chases her down a hallway. Exena runs into a room and attempts to swing the heavy door shut before the dragon gets her. The door is initially perpendicular to the wall, so it must be turned through 90 to close. The door has a height of 3.00 m and a width of 1.30 m, and its weight is 800 N. You can ignore the friction at the hinges. Part A If Exena applies a force of 270 N at the edge of the door and perpendicular to it, how much time does it take her to close the door? Use 9.80 m/s^2 for the acceleration due to gravity.

Explanation / Answer

Here ,

let the time taken is t

Now, Using second equation of motion

theta = 0.50 * a * t^2

theta= 0.50 * (torque/I) * t^2

pi/2 = 0.50 * (270 * 1.30/(1/3 * 800/9.8 * 1.30^2)) * t^2

solving for t

t = 0.64 s

the time taken is 0.64 s

Related Questions

Navigate

• Browse (All)
• Browse W
• Subjects

---

---

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