Question 621:

• JAMB 1991

An object moves with uniform speed round a circle. Its acceleration has

A. Constant magnitude and constant direction
B. Constant magnitude and varying direction
C. Varying magnitude but constant direction
D. Varying magnitude and varying direction

Question 622:

• JAMB 1991

A body of mass 100g moving with a velocity of 10.0ms-1 collides with a wall. If after collision, it moves with a velocity of 2.0ms-1 in the opposite direction, calculate the change in momentum.

A. 0.8Ns
B. 1.2Ns
C. 12.0Ns
D. 80.0Ns

Question 623:

• JAMB 1991

A spring of force constant 1500Nm^-1 is acted upon by a constant force of 75N. Calculate the potential energy stored in the string

A. 1.9J
B. 2.8J
C. 3.45J
D. 0.43J

Question 624:

• JAMB 1991

A wheel and axle have radii 80cm and 10cm respectively. If the efficiency of the machine is 0.85, an applied force of 1200N to the wheel will raise a load of

A. 8.0N
B. 6.8N
C. 8160N
D. 9600N

Question 625:

• JAMB 1991

A 20kg mass is to be pulled up a slope inclined at 30^o to the horizontal. If the efficiency of the plane is 75%, the force required to pull the load up the plane is [g = 10ms^-2]

A. 13.3N
B. 73.5N
C. 133.3N
D. 53.2N