Can you do my homework 2?
- 11 Dec 06, 05:25 PM
Following the huge interest in and bitter disputes over the last lot of homework I posted on this public forum, I present the sequel: Can you do my homework 2?
1. The Earth has a radius of 6,400 km. What is the speed of Edinburgh at a Latitude 56º?
(a) 465 ms-1
(b) 386 ms-1
(c) 260 ms-1
Use the equation for kinetic energy Ek=1/2mv2 and change in gravitational potential energy Ep=mgh for the following questions.
2. A car of mass 850 kg which is moving at a speed of 10 ms-1 is acted upon by a braking force of 1500 N for a distance of 20 m. Calculate the final speed of the car.
(a) 3.81 ms-1
(b) 5.42 ms-1
(c) 7.98 ms-1
3. A 3 kW motor is used to lift a mass of 700 kg a height of 6.5 m. The operation takes 20 seconds. Calculate the efficiency of the motor lift.