What is the focal length of concave mirror that magnifies , by a factor of +3.2 , an object that is placed 30cm from the mirror

Which material produces static charge when rubbed?

An ideal spring has a spring constant (force constant) of 2500 n/m, is stretched 4.0 cm, how much elastic potential energy does it possess? (a) 3j (b) 0.00j (c) 1j (d) 2j (e) 4j

When a 5.0kg cart undergoes a 2.2m/s increase in speed, what is the impulse of the cart