Recent content by Kalvarin

You need to work out it's rotational kinetic energy. I = m*(r^2) I is the moment of inertia of a point mass rotating about a fixed point. Mass of turntable isn't mentioned so assume it is negligible. E = 0.5*I*(w^2) E is the energy of a rotating system, where w is angular frequency...

Np :)

Hi Vo will be 2.5 m/s in the direction the balloon is moving. If it wasn't then if you where in a moving car and you threw a ball it would fly to the back of the car at the speed the car is moving.. and that don't happen :)

To work out the range we need to work out the flight time. So first find the time it takes the ball to reach it's highest point using the y-component of it's velocity. Then calculate how long it takes to hit the floor. The sum of these two times is the flight time.

Yep that looks right.

The electric field is only zero inside a conducting sphere. This is because all the charge migrates to the surface and it acts likes a hollow charged shell. In the question it does not say the sphere is conducting, it says it is uniformly charged. Therefore it must be acting as an insulating...

I've worked through part one and you will get a complicated looking equation for \Theta. I got: (2(u\hat{}2) +2u)*sin\hat{}2(\Theta) + h*sin(\Theta) - 2u = 0 Where u is the initial velocity. If you replace sin(\Theta) with x you can solve for x just like an ordinary quadratic. Then when...

Hi The first part is right. For the second part we know that the normal force (R) is equal to m*g when no other forces are acting on the chair. In this case there is an external force acting on the chair, a component of this force is acting in the upwards y direction. Yet there is no...

You got to get everything in the same units. We have velocity in m/s so we want time in seconds. 1.2 hours = 72 minutes = 4320 seconds Then just use: Distance = Velocity*Time

You need to calculate the distance the rocket travels after the engine fails before it comes to a complete stop.

a b a*b 0 0 0 0 1 0 1 0 0 1 1 1 This is the truth table for the above statement. Don't think of it as an implication. All it is saying is a*b only has a non-zero value when both a and b have values greater than 0.

Oh ok, well then just use your value of omega in the formula anden gave you. That is the time for 1 revolution.

It's 13534 Kg/m^3

Well rpm for a gven radius can infinetly many values. How did you work out the value of omega?

You need to know more data to work out the rpm, knowing just the radius of the centrifuge is not enough.