(adsbygoogle = window.adsbygoogle || []).push({}); 1. 1) What is the maximum possible speed of impact upon the surface of the Earth for a faraway body initially at rest that falls to the Earth by virtue of the Earth's gravity only?

2) A ball is thrown horizontally from a cliff at a speed of 11 m/s. What is its speed one second later?

3) An airplane is flying horizontally with speed 1000 km/h (280 m/s) when an engine falls off.

(a) Neglecting air resistance, if it takes 30 s for the engine to hit the ground how high is the airplane?

(b) If it takes 30 s for the engine to fall how far horizontally does the engine travel while it falls?

(c) If the airplane somehow continues to fly as if nothing had happened, where is the engine relative to the airplane at the moment the engine hits the ground?

(multiple choice)

a) directly below the plane

b) in front of the plane

c) behind the plane

4) Students in lab measure the speed of a steel ball launched horizontally from a table top to be 3.4 m/s. If the table top is 1.5 m above the floor, where should they place a 20 cm tall tin coffee can to catch the ball when it lands?

5) John and Tracy look from their 71 m high-rise balcony to a swimming pool below - not exactly below, but rather 17 m out from the bottom of their building. They wonder how fast they would have to jump horizontally to succeed in reaching the pool. What is the answer?

6) Ignoring air drag, what is the maximum speed possible for a horizontally-moving tennis ball as it clears the net 1.5 m high and strikes within the court's border, 12.0 m distant.

7) Calculate the speed in m/s at which the Earth revolves about the sun. You may assume the orbit is nearly circular.

8) A satellite is about 1.8 103 km from the (center of the) Earth. Find its average orbital speed about the Earth.

2. I'm sorry but i dont know, thats why i'm so confused, these were on www.webassign.com I don't know what formulas to use....

3. umm.... i'm sorry, i don't want this deleated, i have no clue how to solve it... i've been trying and i'm sooo lost, oh and it's due in less then an hour so i dotn know what to do, could someone explain this to me??

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Projectile Motion- Please Help me

**Physics Forums | Science Articles, Homework Help, Discussion**