A body rolls down a slope from a height of 100m. its velocity at the foot of the slope is 20ms-1. What percentage of its initial potential energy is converted into kinetic energy? [g = 10ms-1]
- A. 40%
- B. 35%
- C. 20%
- D. 15%
A constant force of 40N acting on a body initially at rest gives an acceleration of 0.1ms-2 for 4s. Calculate the work done by the force
- A. 8J
- B. 10J
- C. 32J
- D. 160J
An elevator of mass 4800kg is supported by a cable which can safely withstand a maximum tension of 60 000N. The maximum upward acceleration the elevator can have is
- A. 2.5ms-2
- B. 5.0ms-2
- C. 7.5ms-2
- D. 10.0ms-2
A man walks 8km north and then 5km in a direction 60o east of north. Find the distance from his starting point
- A. 11.36km
- B. 12.36km
- C. 13.00km
- D. 14.36km
A jet engine develops a thrust of 270Ns when the velocity of the exhaust gases relative to the engine is 300ms-1. What is the mass of the material ejected per second?
- A. 81.00kg
- B. 9.00kg
- C. 0.90kg
- D. 0.09kg
Which of the following units is equivalent to kgms-1?
- A. Ns-1
- B. Nms-1
- C. Ns
- D. Js-1