Physics - February 2007

pls complete this if u can..


1.) If a motorboat travels 25 km/hr down a river that has a velocity of 4 km/hr, what is the boats actual velocity?
a. 21 km/hr
b. 29 km/hr
c. 100 km/hr
d. 6.2 km/hr



2.) The rate of change of velocity called____
a. speed.
b. motion.
c.momentum
d. acceleration


3.) A distance-time graph is a straight line for
a. constant speed.
b. acceleration
c. momentum.
d. speed

4.) An object traveling in a circular motion is constantly changing

a.speed
b.mass
c.distance
d.direction


Pls people help. =]

2007-02-16 09:51:17 · 6 answers · asked by love<3 3

what are examples of natural satellites,, please give lots of examples!!

2007-02-16 09:47:19 · 6 answers · asked by Anonymous

when does it requirers to run for a doctor ?

2007-02-16 09:46:24 · 5 answers · asked by jack n 1

Is this possiable without breaking the circuit of the p.a system?

2007-02-16 09:34:39 · 2 answers · asked by AntiStyptic 2

2007-02-16 09:27:47 · 10 answers · asked by Anonymous

Thanks...Tom Science 4

2007-02-16 09:06:31 · 4 answers · asked by Anonymous

Three identical 6.60 kg masses are hung by three identical springs, as shown in the figure. Each spring has a force constant of 6.40kN/m and was 16.0cm long before any masses were attached to it. How long is each spring when hanging as shown? (Hint: First isolate only the bottom mass. Then treat the bottom two masses as a system. Finally, treat all three masses as a system.)

2007-02-16 08:32:37 · 1 answers · asked by Anonymous

What should be the spring constant k of a spring designed to bring a 1200 kg car to rest from a speed of 109 km/h so that the occupants undergo a maximum acceleration of 5.0 g?

2007-02-16 08:27:39 · 1 answers · asked by Anonymous

In the high jump, the kinetic energy of an athlete is transformed into gravitational potential energy without the aid of a pole. With what minimum speed must the athlete leave the ground in order to lift his center of mass 2.35 m and cross the bar with a speed of 0.65 m/s?

2007-02-16 08:19:35 · 3 answers · asked by Jessie L 2

An asteroid has acquired a net charge of −115 C from being bombarded by the solar wind over the years, and is currently in equilibrium whereby it expels electrons at the same rate
as it acquires them. How many more electrons does it have than protons?

2007-02-16 08:10:55 · 1 answers · asked by I S 1

How high will a 1.95 kg rock go if thrown straight up by someone who does 70.0 J of work on it? Neglect air resistance.

Answer should be in meters. I'm really just looking for the equation to solve this with. But answers are encouraged. I can compare my results with yours. Thanks.

2007-02-16 07:46:49 · 4 answers · asked by Jessie L 2

So...I don't know how to do physics stuff. I don't even know what equations and what not I'm supposed to be using. But I figure if I can actually see a problem solved, I'll be able to figure out how these things are done.

A truck driver going 100 km/h applies the brakes, giving the truck a uniform decceleration of 6.50 m/s2 while it travels 20.0 m. (a.) what is the velocity of the truck in km/h at the end of this distance? (b.) how much time has elapsed?

2007-02-16 07:33:54 · 5 answers · asked by Anonymous

When you stop to think just what all is involved in this concept, doesn't just make your head spin?

2007-02-16 07:32:36 · 3 answers · asked by Anonymous

I have a circuit it resembles to rectangles. So there are 3 rows connected in parallel. The top row has a 1 ohm resistor. The second row (which is connected to row 1 and 3) has a 2 ohm resistor followed by a 1 volt battery (from left to right). The bottom row has a 3 ohm resistor followed by a volt battery (left to right). So there are 3 resistors and 2 batteries.

What is the magnitude of the current in the 2 ohm resistor?

2007-02-16 07:20:39 · 2 answers · asked by Anonymous

Three uniform spheres of mass m1 = 1.50 kg, m3 = 4.00 kg, and m2 = 7.50 kg are placed at the corners of a right triangle. Where the distance from m1 to m3 is 3.00m in y-direction and the distance from m2 to m3 is -4.00m in x direction. Calculate the resultant gravitational force on the 4.00 kg object, assuming the spheres are isolated from the rest of the Universe.
a) What are i N + j N?

2007-02-16 07:02:12 · 1 answers · asked by Victoroza 1

Neil A. Armstrong was the first person to walk on the moon. The distance between the earth and the moon is 3.85E8 m. Find the time it took for his voice to reach earth via radio waves.

Please show me the steps that lead you to your answer. Thanks!

2007-02-16 06:30:10 · 5 answers · asked by Anonymous

2007-02-16 06:15:30 · 3 answers · asked by mjd 1

Batman, whose mass is 76.0 kg, is holding onto the free end of a 13.0 m rope, the other end of which is fixed to a tree limb above. He is able to get the rope in motion as only Batman knows how, eventually getting it to swing enough that he can reach a ledge when the rope makes a 58.0° angle with the vertical. How much work was done by the gravitational force on Batman in this maneuver?

2007-02-16 06:06:27 · 2 answers · asked by Victoroza 1

horizontal. when teh arrow returns to the same height from which is started,

2007-02-16 05:58:36 · 2 answers · asked by Varun S 1

the time that we follow can be bend or not?

2007-02-16 05:39:31 · 5 answers · asked by Anonymous

A plumb bob does not hang exactly along a line directed to the center of the Earth's rotation. How much does the plumb bob deviate from a radial line at 32.5° north latitude? Assume that the Earth is spherical.

answer is wanted in degrees

2007-02-16 05:36:25 · 3 answers · asked by sabresfan58 1

2007-02-16 05:29:15 · 3 answers · asked by aquosrouge 1

If you travel faster than the speed of light, will you be able to see anything? Or will it just be dark?

2007-02-16 05:09:56 · 30 answers · asked by Bishonen Panda 1

Need help solving a problem
A cat chases a mouse across a 1.3 m high
table. The mouse steps out of the way, and
the cat slides out of the table and strikes the floor
1.8 m from the edge of the table.
The acceleration of gravity is 9.81 m/s2 :
What was the cat's speed when it slid of
the table?

I dont think is possible for this problem to be done since I dont have the time it took for the cat to hit the floor. Can anybody help me if is possible

2007-02-16 05:08:37 · 2 answers · asked by theguy 2

My reconning is that the technology must exist to activate lights as needed from a distance... but then doesn't leaving a light on for an hour use less electricity than the act of switching on and off? (Sure I heard something along that theory before but not sure)

2007-02-16 04:43:58 · 7 answers · asked by Monkster 3

At the tropics, it's bigger than 200 kcal/cm2. At the Ecuator, it's 180 kcal/cm2. What's the reason of this? Explain thoroughtly.

2007-02-16 04:22:19 · 2 answers · asked by Anonymous

2007-02-16 04:08:49 · 19 answers · asked by twet 1

particles A and B, of masses 0.15kg and 0.2kg respectively, are free to move on a horizontal surface. air resistance may be ignored. at a particular instant A is moving with speed 2ms-1 towards B, which is stationary at a point 4m from A. particle A collides directly with particle B.

it is given instead that the coefficient of friction between A and the surface is 0.05. A is again brought to rest by the collision. Find the speed of B immediately after the collision?

2007-02-16 03:43:13 · 3 answers · asked by Leonidus 2

2007-02-16 03:26:05 · 6 answers · asked by hollis 1

in physics... when an object does work its loses energy and the energy gets transferred to an other object on which the work is being done... so when a car moves... the car is doing some work as it causes displacement and force is applied.. then where does the energy of the car gets transferred to???

2007-02-16 03:09:32 · 4 answers · asked by trisha 2