This is simply looking at the position kinematic equation for the two different components of the velocity. You know the following is definitely true, which you'll need to find the initial speed of the pellet:

1. Gravity will affect the y component only, therefore the x-velocity will be constant.

2. Y component will not have an initial velocity since the gun will be shot horizontally.

3. The vertical distance will help you obtain the time it took for the gun to get from the gun to the target.

You should be very careful here because you need a clearer understanding of the relationship between velocity and Power.

With velocity you know how much energy was used. In this case you would be considering kinetic energy (T). Additionally, power is simply the amount of energy used for a specific amount of time. Since total energy is T in this case then you simply consider that n times a certain energy is also n times the original power. On top of the being true, T α v^2.

With this information you should know how to solve the problem.

The general approach to these problems are the following steps:

1. Set up a diagram of all the forces which are possible. In this case there are 2 forces of friction and the force of gravity.

2. Balance the forces out using Newton's second law, except find it for when acceleration is zero since that is the limit where there would be a change and there would be an unbalance of forces. (Include the force which is caused by the pulling motion)

3. Lastly, don't forget to solve for the extra F which should be included to account for the force that is causing the pulling motion.

I'm going to assume you are referring the speed in the y-direction. If that is the case, then yes there will always be a zero at the top point of a trajectory, especially in simple cases such as in our regular everyday gravitational experiences.

• If your answer is surprisingly small, then air resistance must be a major factor. If you calculated that the record throw required 10 N of force, you know something must be up because that sounds easy to beat.

These cookers have high temperature and pressures inside. By letting it cool, you let the pressure settle down as well. Right after it is "done" cooking it is dangerous to open

Ok we have 2 forms of potential, kinetic and gravitational potential, and two sources of work, the driving force and friction.

The driving force is what is giving the box energy, so let's start with that. It gives The box energy so the work it does is positive. W= F*d. These values are given, so that part is easy.

Next, it takes energy to go up the ramp because gravitational potential is increasing. U=mgh, so subtract that from the work done by the driving force.

The last piece is the work done by friction. This takes energy from the block. First you have to figure out the force of friction. This can be done with Newton's Secind law, and is much easier if you draw a diagram! Again, W =F*d. We know the work should be negative, and it is because F&d point in opposite directions. Subtract this from our running energy and you are left with kinetic energy.

In an equation, this looks like KE+U_grav=W_drive+ W_friction

Hope this helps!

It will when there is nothing on it, but when you put a mass on one side, it will want to tip, so you must move the fulcrum so that all torques cancel. If you draw a picture and label all the forces( there are only 3), it should make sense. Only 2 forces will cause torque, so they must be equal in magnitude for there to be no net torque.

Hope this helps!

Yes, the kinetic energy is equal to the change in potential energy. and since it is not a point mass,

KE = 1/2 m*v^2+1/2 I* w^2, where v=r*w (no-slip condition)

Hope this helps!

For a hemisphere, the volume is 2/3 * pi * r^3. If the frog-pod combo isn't sinking, then its density must be less than the density of the fluid. Density of an object can be found by mass/volume.

This gives us the equation m/V < D_fluid

Hope this helps!