Question 436:

• JAMB 1987

A man walks 8km north and then 5km in a direction 60^o east of north. Find the distance from his starting point

A. 11.36km
B. 12.36km
C. 13.00km
D. 14.36km

Question 437:

• JAMB 1987

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

Question 438:

• JAMB 1987

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

Question 439:

• JAMB 1987

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%

Question 440:

• JAMB 1987

The coefficient of static friction between a 40kg crate and concrete surface is 0.25. Find the magnitude of the minimum force needed to keep the crate stationary on the concrete base inclined at 45o to the horizontal. [G = 10ms-1]

A. 400N
B. 300N
C. 283N
D. 212N