# Posts by physics

Total # Posts: 436

**Physics**

here's another one that i have no idea how to do If a car is accelerating downhill under a net force of 3674 N what force must the brakes exert to cuase the car to have a constant velocity?

**Physics**

well the net force is obivuosley greater than friction sense it's moving allowing it to move 20 m/s f=ma i don't know the mass so I don't know what to do here?

**Physics**

I don't see how I have enough information to answer this question If a car is traveling westward with a constant velocity of 20 m/s what is the net external velocity

**physics**

odd i never seen this formula before and we haven't goten to tension yet thank you

**physics**

A 5.0 kg bucket of water is raised form a well by a rope. If the upward acceleratiopn of the bucket is 3.0 m/s^2 find the force exerted by the rope on the bucket of water what exactly do i do here? 3.0 m/s^2 upward? is this the Fn? I have no idea how to do this problem...

**Physics**

A 2.0 kg mass starts from rest and slides down an inclined plane 8.0 X 10^-1 m long in .50s. what net force is acting on the mass along the incline. I have no idea how to do this I don't know why they just didn't say .8m the back of the book says 13 N down the incline ...

**Physics**

A box slides down a 30.0 degree ramp with an acceleration of 1.20 m/s^2. Determine the coefficient of kinetic fiction between the box and ramp. I'm not exactly sure what to do here I know the formulas are uk = Fk/Fn Us = Fs, max/Fn not exactly sure how to do this problem ...

**Peter**

A 200 N/m, 5 m spring on a 20 degree incline is compressed 2.3 m and a 5 kg block is placed on it. If we neglect friction, how far up the incline will the block travel? How fast will it be traveling when it is 0.2 m up the incline?

**physics**

please answer my question below

**Physics**

sigh this is killing me here... ok rockets launch at 250 m/s @ an angle of 75.0 degrees. There's a mountain 2500m away from launch point that is 1800m high. There's a boat 610 m from the island. So i'm suppose to find out how much it'll clear the moutain and ...

**physics**

sigh this is killing me here... ok rockets launch at 250 m/s @ an angle of 75.0 degrees. There's a mountain 2500m away from launch point that is 1800m high. There's a boat 610 m from the island. So i'm suppose to find out how much it'll clear the moutain and ...

**physics**

i have to build a catapult that will fire a projectile that will pass a 1m tall wall 1 m away from starting point and land in a target 1 m away from the wall. the catapult cant be more than 23cm high. I'm having some problems here with this for simpicity issues i said ...

**physics**

the other physics question

**physics**

please my post from earlier

**physics**

What gives? projectile launched @ 10.0 m/s @ 45.0 degrees figured everyhting out go these three points I'm trying to apply my Algebra 2 class stuff to it to get the equation of the perabala (0,0) (5.1 , 20.4) (10.2 , 0 ) then i use matrix to find the values and my equation...

**physics**

how does tan give me direction?

**physics**

a ugst of wind blows an apple from a tree. AS the apple falls the force of gravit on the apple is 9.25N downward and the force of the wind on the apple is 1.05N ot the right. Find the magnitude and direction fof the external force on the apple

**physics**

A craet is pulled right with a force of 82.0 N to the left with a force of 115N upward with a force of 565N and dow ward with a force of 236N Find the net external force in the x direction find the net external force in the y directin find the magnitude and direction of the ...

**Physics**

A crate is pulled right with a force of 82.0N to the left wtih a force of 115N upward with a force of 565N and downward with a force of 236N Fine the net external force in the X direction Find the net external force in the y direction find the the magnitude and direction of ...

**physics**

I need some help getting a formula. I remember in class u get this really wierd looking equation like Vicosg-((vsin(pheta))/2g) I think this is what the equatin is when I'm asked to "Derive a formula for the Range of a projectile based on Vi and the Launch angle, ...

**Physics**

I need some help getting a formula. I remember in class u get this really wierd looking equation like Vicosg-((vsin(pheta))/2g) I think this is what the equatin is when I'm asked to "Derive a formula for the Range of a projectile based on Vi and the Launch angle, ...

**Physics**

Is the answer for the 1st question ...23.5 rad/ sec? Is the answer for the 2nd question...66 times? Is the answer for the 3rd question...3382.5 meters?

**Physics**

I need help with solving these word problems. Marion rides her racing bicycle @ speed of 8 m/s. Bicycle wheels have a radius of 34 cm. What is the angular speed of wheels? How many times does each wheel go around during a 10-min race? A car tire has radius of 33cm. Tire turns...

**physics**

I need help with solving these word problems. Marion rides her racing bicycle @ speed of 8 m/s. Bicycle wheels have a radius of 34 cm. What is the angular speed of wheels? How many times does each wheel go around during a 10-min race? A car tire has radius of 33cm. Tire turns ...

**sara**

In a constant-volume process, 211 J of energy is transferred by heat to 1.05 mol of an ideal monatomic gas initially at 303 K. (a) Find the increase in internal energy of the gas. J (b) Find the work done on it. J (c) Find its final temperature. K i am having trouble with this...

**sara**

In a constant-volume process, 211 J of energy is transferred by heat to 1.05 mol of an ideal monatomic gas initially at 303 K. (a) Find the increase in internal energy of the gas. J (b) Find the work done on it. J (c) Find its final temperature. K i am having trouble with this...

**tom**

The sound emitted by bats has a wavelength of 3.0 mm. What is the sound's frequency in air? how do i do this??

**Chels**

What can you say about the motion of a body if its veloctiy-time graph is a straight line inclined with the time axis? a. the body moves with uniform velocity b.the body moves with uniform acceleration c. the body moves with non uniform acceleration d. the body moves with ...

**Jenish**

Suppose you want to run some apparatus that is 95 m from an electric outlet. Each of the wires connecting your apparatus to the 120 v source has a resistance per unit length of .0065 ohms/m. If your apparatus draws 3.0 A what will be the voltage drop across the connecting ...

**Jenish**

A 1200 W hair dryer is designed for 117 v. a) What will be the percentage change in power output if the voltage drops to 105 v. b) How would the actual change in resistivity with temperature affect your answer.

**natali**

A 100W light bulb is left on for 10hrs. Over this period of time how much energy is used by the bulb? am i doing this right? my guess is to convert 100W to kW and convert 10 hrs to seconds and multiply the 2 together? which gives 3600J or should i just leave it in watts?

**mojo**

A hydrogen atom is in its elevnth excited state, n = 12. Using the Bohr model of hydrogen, find the linear momentum. You want to solve for the electron velocity and multiply that by the electrn mass. There are many ways to do this. One would be to get the radius of the orbit ...

**micole**

White light strikes a diffraction grating (930 lines/mm) at normal incidence. What is the longest wavelength that forms a second-order maximum? I used the equation [(1/d)sin(90)]/m = wavelength: [(1/0.93m)(1)] /2 = 0.5376m. To convert to nm I multiplied by 10^-9. This is ...

**susane**

I have a question concerning waves. What effect does increasing the tension in a vibrating string have upon wavelength? I was thinking that as the weight increases more standing waves are created. As more standing waves are created, the wavelength decreases. I have one more ...

**tatiana**

A car tire of radius 45cm turns at a constant 14 rads/s. For a point on the edge calculate a) the tangential V b) the tangential a c) the centripetal "a" work: a) v= rw v= .45m * 14 rads/s= 6.3m/s b) at=alphar alpha= w/t I am unsure how to get time? c) at= w^2r at= ...

**science**

A 59-kg housepainter stands on a 13-kg aluminum platform. The platform is attached to a rope that passes through an overhead pulley, which allows the painter to raise herself and the platform. (Ignore the mass of the pulley and any friction in the pulley.)