This is where I get confused with Physics. Are speed and velocity the same thing?
Redoing the math, which I hope is right:
Avg speed is (10 rad/s + 8 rad/s) / 4 s = 4.5 rad/s
Vt = r*w = 4 m * 4.5 rad/s = 18 rad/s
Or do I not need to go as far to find Vt?
Homework Statement
A grindstone of radius 4.0m is initialy spinning with an angular speed of 8.0 rad/s. The angular speed is the increased to 10rad/s over the next 4.0 seconds. Assume that the angular acceleration is constant. What is the average angular speed of the grindstone?
Homework...
I have to program the range formula R= [Vo2sin(2*theta)]/g, into an Excel spredsheet. I need to progran the equation for various values of 'theta' to determine for which value(s) of 'thet' is the range maximum.
Table should have left side Injection angle (degrees), right side Range (R). The...
OK, think I got it now:
V= m/p
Air = 15.76 / 8470
= 1.8 x 10^-3
Water = 13.86 / 8470
= 1.6x10^-3
Difference of the two is 2x10^-4, which happens to be one of the answers.
What I did is find the volume of the brass in the air, then the volume in the water and found the difference between the two. This is not the correct answer though. What did I do wrong?
A small sculpture made of brass (p = 8470 kg/m^3) is believed to have a secret central cavity. The weight of teh sculpture in air is 15.76N. When it is submerged in water, the weight is 13.86N. What is the volume of the secret compartment?
Fb = W
W = pgV
15.76 = 8470 * 9.8 * V
15.76 =...
An ice cube, p = 917 kg/m^3, is sliding down a 16 degree frictionless incline. The sides of the cube each have a length of .75 m. What pressure does the cube exert on the incline?
P = F / A
= F / .75^3
= F / .42
F = ma
= 917 * a
I am having a problem figuring out the Force...
A 50kg rider on a moped of mass 75kg is traveling with a speed of 20 m/s. Each of the two wheels of the moped has a radius of 0.2m and a moment of inertia of 0.2 kg*m^2. What is the total rotational kinetic energy of teh wheels?
KEr = 1/2Iw^2
= 1/2(.02)(20)^2
= 4
Two wheels = 2...
The conservation of energy states that the total of all energies before the process is equal to the total energies after the process.
Forgive me, but I am not understanding how to apply that to this problem. :(
A ping-pong ball weighs 2.5x10^-2N. The ball is placed inside a cup that sits on top of a vertical spring. If the spring is compressed .055m and released, the maximum height above the compressed position that the ball reaches is 2.84m. Neglect air resistance and determine the spring constant...
Is there a difference between the two? The problem reads:
A grindstone of radius 4.0m is initially spinning with an angular speed of 8 rad/s. The angular speed is then increased to 10 rad/s over the next 4 seconds. Assume that the angular acceleration is constant. What is the average angular...
Just checking to see fi I did the math right:
During the spin-dry cycle of a wash, the motor slows down from 95 rad/s to 30 rad/s while turning the drum through an angle of 402 radians. What is the magnitude of the angular acceleration of the motor?
= 1/2(Wo + W)t
402 = 1/2(95 +...
If I was given 477 rev/min and I need to convert to radians, I would use:
477rev (2*pi radians/1 rev) = 2997.07 radians
Question is do I need to divide by 60 to get radians/second instead of minutes?
WOW! I brain farted that one. For some reason I was thinking to replace the "a*t" with 27. Don't know why... Thank you for your help, I really appreciate it.
An 810-kg car accelerates from rest to 27m/s in a distance of 120m. What is the magnitude of the average net force acting on the car?
120m / 27m/s= 4.4 s
F=ma
=810kg * 4.4s
= 3600 N
This is not one of my choices. What did I do wrong?
I think I have been staring at this question too long as I can not figure it out. I am sure the answer is simple:
A 1500-kg elevator moves upward with a constant speed through a vertical distance of 25m. How much work was done by the tension in the cable?
I know that W= (F cos 0)s, and...