Recent content by Andrew1234

According to the solution to the related example problem in the book B and D have no linear velocity because they are at the lower limit of their respective motion ranges. I don't see why the angular velocities are not also zero, because the panels must also stop rotating. Also from this...

If an analogy is drawn to kinematics problems in which for example a ball is thrown from a height h, when it strikes the floor it has a final velocity although it stops moving instantaneously. But in this problem, the points B and D have no linear velocity when E strikes the floor. Their final...

Thank you for clarifying this concept

Is there a mathematical explanation for why the work done in the condenser (in process 2 to 3) is zero? I am aware that ammonia does not expand or compress in the condenser, only changes phase, but without knowing that the process takes place in a condenser and only considering the graph...

Yes, I understand the solution up to that point I think I see how to solve the problem now, using the relation Cp = Cv+R Thank you for your help

Thank you for your response.

Yes I am familiar with the open system energy balance

The solution can be found at https://study.com/academy/answer/an-insulated-rigi... After using the two equations I can't see why (h2-h1)/(u2) should equal (T2)/(T1). Can someone explain why specific heat ratio is equal to temperature ratio?

α is the second derivative of angle and w is the first derivative In the free body diagrams the only force on A is the normal force since it is only constrained not to move vertically. Have I drawn the free body diagram and kinetic diagram correctly? By relating the accelerations of the...

Do you mean that it is possible for the plunger when released to give the ball, which is initially at rest, both an initial velocity and acceleration?

Thanks for the clarification. I asked the question because it was not clear to me that the ball when released from the track has no initial velocity but accelerates forward, but thought that when the plunger comes in contact with it gives it a velocity rather than an acceleration.

Why is energy balance for a control volume dE/dt = dQ/dt-dW/dt-dm/dt(ΔH+ΔKE+ΔPE) 0 = dQ/dt-dW/dt-dm/dt(ΔH+ΔKE+ΔPE) whereas for other systems it is ΔE =Q-W-(ΔU+ΔKE+ΔPE) 0 = Q-W-(ΔU+ΔKE+ΔPE) with enthalpy, h = u +pv, replaced by only the internal energy? How is the pv term accounted for...

I know how to solve the problem but have a question related to it. When the block is initially released from the spring the spring, having been pulled back, should give an initial velocity to the block. In that case why is the block's initial velocity zero?

I think I understand how to solve the problem using the system's free body diagram but not if the truck's and crate's free body diagrams are considered separately. Let m and s represent the crate's mass and stopping distance and M and S represent the truck's mass and stopping distance. In terms...

Thank you for your response. Doesn't this equation lead to the same conclusion since the braking and friction forces oppose each other? Kinetic energy is positive, so if the friction opposes the braking force d must be larger if the crate slides.