IB Physics A.3 Work, Energy and Power Questionbank

A spring with spring constant $k = 300\ \text{N m}^{-1}$ is compressed by $0.20\ \text{m}$ and used to launch a $2.0\ \text{kg}$ cart along a horizontal surface with $20\%$ of the energy lost due to friction. What is the final speed of the cart?

A machine lifts a $500\ \text{kg}$ load vertically upward at a constant speed of $2.00\ \text{m s}^{-1}$. The gravitational field strength is .

A block of mass $m$ slides down a rough incline of length $L$ and angle $\theta$. The coefficient of dynamic friction is $\mu_d$. The block starts from rest and reaches the bottom with speed . What is the correct expression for the energy dissipated by friction?

The energy consumption of a device is shown by the Sankey diagram below:

What is the efficiency of this device?

A $2.5\ kg$ object is attached to a spring ($k = 400\ N\ m^{-1}$) and compressed on a frictionless horizontal surface. It is then released. After leaving the spring it slides onto a rough patch of length , where it travels the full before coming to rest. What is the average resistive force exerted by the rough patch?