| A | B |
|---|
| At room temperature, an oxygen molecule, with mass of 5.31 x 10^-26 kg, typically has a KE of about 6.21 x 10^-21 J. How fast is it moving? | ??? |
| How much work is required to stop an electron (m = 9.11 x 10^-31 kg) which is moving with a speed of 1.90 x 10^6 m/s? | ??? |
| How much work must be done to stop a 1000-kg car traveling at 110 km/h? | ??? |
| A spring has a spring constant, k, of 440 N/m. How much must this spring be stretched to store 25 J of potential energy? | ??? |
| By how much does the gravitational potential energy of a 64-kg pole vaulter change if his center of mass rises about 4.0 m during the jump? | ??? |
| In starting an exercise, a 1.60-m tall person lifts a 2.10-kg book on the ground so it is 2.20 m above the ground. What is the potential energy of the book relative to (a) the ground, and (b) the top of the person's head? | ??? |
| A 55-kg hiker starts at an elevation of 1600 m and climbs to the top of a 3100-m peak. What is the hiker's change in potential energy? What is the minimum work required for the hiker? | ??? |
