If only an external force can change the velocity of a body, how can the internal force of the brakes bring a car to rest? 1. it is the driver, not the car itself who causes the breaking, so it is an external force. 2. the engine is stopped, so the car has no force to run further. 3. some internal forces can change the velocity of a body. 4. it is the force of the road on the tires (an external force) that stops the car.

Amass has an acceleration of 10- 2t. what is its velocity and displacement if it started at x- 4m and the initial velocity was 8m/s? at what time does it have 0 velocity? graph all graphs.

Electroplating is a way to coat a complex metal object with a very thin (and hence inexpensive) layer of a precious metal, such as silver or gold. in essence the metal object is made the cathode of an electrolytic cell in which the precious metal cations are dissolved in aqueous solution. suppose a current of 480.ma is passed through an electroplating cell with an aqueous solution of agno3 in the cathode compartment for 46.0 seconds. calculate the mass of pure silver deposited on a metal object made into the cathode of the cell. round your answer to 3 significant digits. also, be sure your answer contains a unit symbol. ×10μ

If forces acting on an object are unbalanced. true or false