Physics - October 2007

Ok i noe what ur gonna say. That i sould do my own homework and stop asking but i have tried these 2 question like a million times and i cannot figure them out.
Please help

1) Assuming no air resistance, how long does it take a penny to fall if it was thrown down with an initial velocity of 5.0m/s from the CN Tower (553m)?

2) Superwoman is hovering above the ground when a person free-falling goes by her at a terminal velocity of 39 m/s. Unfortunately, the parachute doesn not open. Fortunately, Superwoman is around. If it takes her 1.9s to realize the person is in distress, what must her acceleration be if she is to catch the parachutist just before she hits the ground 1000m below.?

Please help
U dont have to jus tell me the answers... even if u jus help me understand them it would be much appreciated. If u do show me how to get the answer.. Please show the steps and explain. Thank You in Advance.

2007-10-03 13:07:31 · 4 answers · asked by Anonymous

I think that g's of acceleration are just a/9.8, right? Not sure how to set up this problem...

You read about a car accident in the newspaper. A car traveling at 70 km/h collided with a concrete bridge support. The front end of the car was compressed 0.92 m, and the car came to a complete stop within this distance.

How many g's of acceleration did the occupant of the car experience?

I feel like I need to know his mass or something, but no other info is given??

2007-10-03 13:07:25 · 4 answers · asked by lilrnblover86 4

the landing speed of a space shuttle is 347 km/h.if a shuttle is landing at a angle of 15 degrees with respact to the horizontal,what are the horizontal and the vertical componets of its velocity? THANK YOU SO MUCH...

2007-10-03 13:01:35 · 1 answers · asked by Regina 1

1.
(a)Calculate the work done in lifting a 520 N barbell 2.4 m above the floor
(b)What is the potential energy of the barbell when it is lifted to this height?

2.
Suppose an automobile has 3100 J of kinetic energy.
(a)When it moves at twice the speed, what will be its kinetic energy?
(b)What's its kinetic energy at three times the speed?

2007-10-03 13:00:33 · 3 answers · asked by atlz1anonly 1

Please xplain your answer. your help is graetly appreciated :)

2007-10-03 12:54:58 · 6 answers · asked by MiCk 2

2007-10-03 12:40:46 · 1 answers · asked by New York 1

Electrons (m = 9.109x10-31 kg) are accelerated from rest theough an electric potential difference of 305 V. They then enter a uniform magnetic field B = 0.200 T that is perpendicular to their direction of motion.

2007-10-03 12:39:11 · 1 answers · asked by Kelly 1

a ball is launched at 30angle above horizontal. what launch speed is required so that the kiwi will land in basket 35 meters distant across level ground

2007-10-03 12:36:06 · 2 answers · asked by alkesh831 2

2007-10-03 12:13:29 · 7 answers · asked by lord_andys_new_id 1

Does anyone know how one could make a Piezoelectricity Science Fair Project. I have a few ideas. For example, I could measure how "conductive" the crystal would get that I would use as I exert more pressure on it. I could see if there's some sort trend, but does anyone know which crystals I would have to use? Are there any that would be cheap to get, but would work very well? Thanks for any help!

2007-10-03 12:08:35 · 4 answers · asked by magixter 2

An airplane pilot wishes to fly due west. A wind of 90.0 km/h is blowing toward the south.

If the airspeed of the plane (its speed in still air) is 310.0 km/h, in which direction should the pilot head?
What is the speed of the plane over the ground?

2007-10-03 12:07:23 · 1 answers · asked by Anonymous

A)Neglecting air friction, what initial velocity would achieve this result?


B)Using the initial velocity found in item a above, determine the maximum height reached by the gold ball.


please help me genius people! i'll appreciate it forever!!

2007-10-03 12:01:44 · 1 answers · asked by a idiot with dreams of wiseman 1

Two vectors have their tails connected and their lengths fixed. If the angle between them is now varied,.....
which of the following is true?

i. The magnitude of the dot product is minimized when the vectors are perpendicular.
ii The magnitude of the dot product is maximized when they are perpendicular.
iii Each will always have a component lying along the other.

a.) i only
b.) ii only
c.) iii only
d.) i and ii only
e.) i and iii only
f.) i, ii, and iii

2007-10-03 11:51:46 · 2 answers · asked by Alex M 1

I'm having trouble understanding the concepts of tension in this problem. Two 1.6kg blocks are connected by a rope. A second rope hangs beneath the lower block. (The diagram is vertical - one block with another block below connected by a rope and that block with a rope beneath it). Both ropes have a mass of 250g. The entire assembly is accelerated upward at 4.0m/s^2 by force F. What is F? What is the tension at the top end of the rope connecting the two blocks? at the bottom end? What is the tension at the top end of the rope beneath the second block?

2007-10-03 11:40:23 · 2 answers · asked by gogiapeach33 2

I'm asking this in terms of a physic's question. The chapter it is on is Momentum in one Dimesion.

2007-10-03 11:17:02 · 7 answers · asked by werewulf2000 2

1. On the base of a bulb is written: 3V, 0.15A. What does this mean?
What will happen if this bulb is connected to a 1.5V cell??

What will happn if it is connected to a 4.5 V battery??

2. For the same voltage, what happens to a current when power is doubled??
what is the power when current is halved???

thanks of answers..!

2007-10-03 11:07:53 · 2 answers · asked by Marvin Shane 2

2007-10-03 10:45:44 · 1 answers · asked by bea e 1

from the horizontal. Neglecting air resistance, find:


a)The Shell's horizontal range





please save me!! I can only rely on geniuses of this world cause i am so stupid but a simpleton like me would do anything for you later so help me!!

2007-10-03 10:43:30 · 1 answers · asked by a idiot with dreams of wiseman 1

cant you just eventually leave a planets gravitational pull at any speed, it'll just take more time?? if so, then how is esacape velocity different?

2007-10-03 10:29:51 · 3 answers · asked by rascalover7 2

2007-10-03 10:24:24 · 2 answers · asked by Anonymous

Can someone break this down in steps for me that I can follow? I am lost, and would like to learn how to do the problem. Thank you!

Only two forces act on an object (mass = 2.80 kg), as in the drawing. (F = 53.0 N.) Find the magnitude and direction (relative to the x axis) of the acceleration of the object. magnitude

2007-10-03 10:18:43 · 2 answers · asked by yummy_girlscout 1

2007-10-03 10:04:37 · 5 answers · asked by Anonymous

WE shot two equal sized balls out of a shooter at 80 degrees and 10 degrees, but they didn't land near the same area like they are suppossed to. Why could this happen?

2007-10-03 10:03:06 · 4 answers · asked by miller20817 3

This is based on knowing the muzzle velocity of the gun, and the distance of the target. Hint: You will need a trig. identity.

2007-10-03 09:42:28 · 2 answers · asked by Anonymous

How far does it move horizontally?
_m
How far does it move vertically?
_m

2007-10-03 09:37:34 · 1 answers · asked by Anonymous

A baseball (m = 154 g) approaches a bat horizontally at a speed of 40.6 m/s (90.8 mi/h) and is hit straight back at a speed of 54.0 m/s (121 mi/h). If the ball is in contact with the bat for a time of 1.03 ms, what is the average force exerted on the ball by the bat? Neglect the weight of the bat, since it is so much less than the force of the bat. Choose the direction of the incoming ball as the positive direction.

2007-10-03 09:30:08 · 1 answers · asked by txsweetpea512 1

A 2.00 kg block is held in equilibrium on an incline of angle = 60° by a horizontal force applied in the direction of the increasing incline. If the coefficient of static friction between block and incline is µs = 0.300, determine the following.:


(a) the minimum value of force/vector F: ____ N
(b) the normal force exerted by the incline on the block: ____ N


Would somebody kindly show me how to do this, step by step, and show your work and the answer? I'm stuck.

2007-10-03 09:23:36 · 1 answers · asked by justme 4

In an inertial frame two particles are shot out simultaneously from a given point, with equal speeds v, in orthogonal directions. What is the speed of each particle relative to the other?

2007-10-03 09:10:15 · 3 answers · asked by KPL 1

Let's say your textbooks have a total mass of 3.0kg. What would the mass of the books be if they were taken to Jupiter where the acceleration due to gravity is 10 times that of Earth?

2007-10-03 09:06:48 · 9 answers · asked by Anonymous

A physics book slides off a horizontal table top with a speed of 1.05 . It strikes the floor after a time of 0.370 . Ignore air resistance.

-Find the height of the table top above the floor.
-Find the vertical component of the book's velocity just before the book reaches the floor.
-Find the magnitude of the book's velocity just before the book reaches the floor.
-Find the direction of the book's velocity just before the book reaches the floor.(an angle)

I found the horizontal distance from the edge of the table to the point where the book strikes the floor to be 0.389 m, and the horizontal component of the book's velocity to be 1.05m/s

but i can't figure out the rest....please help

2007-10-03 09:03:35 · 2 answers · asked by sandymandy 1