Mechanics homework help

Physics 210                                                   Homework 4                                                                 Dr. Kotowich
Directions: Answer all questions and provide full details, no work means no credit.

• A jet is flying horizontally at an altitude of 20 km with a velocity of 2500 km/h when the engine falls off.

1. How long does it take the engine to hit the ground?
2. How far horizontally is the engine from where it fell off when it hits the ground?
3. How far is the engine from the aircraft when the engine hits the ground?

• A projectile is fired with an initial velocity of 30 m/s at 60 degrees to the horizontal. At the projectile’s highest point what is its velocity and acceleration?
• A boy whirls a ball on a string in a horizontal circle of radius 1 m. How many revolutions per minute must the ball make if its acceleration towards the center of the circle is to have the same magnitude as the acceleration due to gravity?
• A plane flies at a speed of 250 km/h relative to still air. There is a wind blowing at 80 km/h in the northeast direction. (That is 45 degrees to the east of north)

1. In what direction should the plane head so as to fly due north?
2. What is the speed of the plane relative to the ground?