Question 4136:

• JAMB 2021

I. A liquid boils when its saturated vapor pressure is equal to the external pressure
II. Dissolved substances in pure water lead to an increase in the boiling point.
III. When the external pressure is increased, the boiling point increases.
IV. Dissolved substances in pure water decreases the boiling point

Which of the above combinations are peculiarities of the boiling point of a liquid?

A. I, II and III only
B. I, II, III, and IV
C. I, II, and IV
D. II, III, and IV

Question 4137:

• JAMB 2021

A lead bullet of mass 0.05kg is fired with a velocity of 200ms\(^{-1}\) into a block of mass 0.95kg. Given that the lead block can move freely, the final kinetic energy after impact is?

A. 50J
B. 100J
C. 150J
D. 200J

Question 4138:

• JAMB 2021

A ball of mass 0.1kg is thrown vertically upwards with a speed of 10ms\(^{-1}\) from the top of a tower 10m high. Neglecting air resistance, its total energy just before hitting the ground is? (Take g = 10ms\(^{-2}\))

A. 5J
B. 10J
C. 15J
D. 20J

Question 4139:

• JAMB 2021

A car of mass 800kg attains a speed of 25m/s in 20secs. The power developed in the engine is?

A. 1.25 x 10\(^{4}\)W
B. 2.50x 10\(^{4}\)W
C. 1.25 x 10\(^{6}\)W
D. 2.50 x 10\(^{6}\)W

Question 4140:

• JAMB 2021

When the breaks in a car are applied, the frictional force on the tyres is?

A. A disadvantage because it is in the direction of the motion of the car
B. A disadvantage because it is in the opposite direction of the motion of the car
C. An advantage because it is in the direction of the motion of the car
D. An advantage because it is in the opposite direction of the motion of the car