4. The potential difference between the terminals of an electric heater is 60 V when it draws a current of 4 A from the source. What current will the heater draw if the potential difference is increased to 127.5 V ?
10. A 4 kg object is moving horizontally with a speed of 5 m/s. To increase its speed to 10 m/s, the amount of net work required to be done on this object is: