A concave shaving mirror has a radius of curvature of 25.0 cm. For each of the following cases, find the magnification and determine whether the image formed is real or virtual and upright or inverted,
(a) an upright pencil placed 46.0 cm from the mirror
(b) an upright pencil placed 5.0 cm from the mirror

Keneila is attempting to ski down a 20 m high friction free hill for the first time. she has a speed 10 m/s at the top. what is her kinetic energy when she is a the bottom, 20 m ? (a)2500 j (b)9800 j (c)12300 j (d)3100j (e)15000j

We put a force of 50n on an object and the acceleration is 100 m/s². what is the mass of the object?

An insulated thermos contains 148 g of water at 72.7 ˚c. you put in a 11.7 g ice cube at 0.00 ˚c to form a system of ice + original water. the specific heat of liquid water is 4190 j/kg•k; and the heat of fusion of water is 333 kj/kg. what is the net entropy change of the system from then until the system reaches the final (equilibrium) temperature?