A3.0 kg ball tied to the end of a 50 cm long string being swung in a circle in a horizontal plane at constant speed. if the tension of the string is 3.8 n, what is the speed of the ball?
question 31 options:
a)
1.2 m/s
b)
1.0 m/s
c)
1.4 m/s
d)
0.8 m/s

Anne applies a force on a toy car and makes it move forward. what can be said about the forces acting on the toy car at the moment anne applies the force?

What is the name of the perceived change in a sound wave’s frequency due to motion between the observer and the sound source?

Materials will have different energies associated with the electrons inside them. this is related to how strongly bound they are by their work function. if we sandwich a material with a very low energy between two materials with a high energy, we create a trap for an electron. if this trap is very narrow in one direction in comparison to the others, this is approximately a 1-dimensional box that confines the electron. what is the lowest energy of an electron in the box if the thinnest direction across the materials is 4.81 nm?