physics

The terminal velocity of a ball-bearing falling through a viscous fluid reached when the?

A. upthrust is equal to the weight of the ball B. ball accelerate uniformly C. upthrust is equal to the…

4 years ago

A body of mass 12kg traveling at 4.2ms‾¹ collides with a second body of mass 18kg at rest. Calculate their common velocity if the two bodies coalesce after collision

A. 1.5 ms‾¹ B. 1.4 ms‾¹ C. 2.1 ms‾¹ D. 1.7 ms‾¹ Correct Answer: Option D = 1.7 ms‾¹ Explanation…

4 years ago

A car accelerate uniformly from rest at 4 ms‾². How far will it travel in the fifth complete second?

A. 100 m B. 50m C. 32 m D. 18 m Correct Answer: Option D = 18 m Explanation From…

4 years ago

When a pentavalent impurity is added to a pure semiconductor; it becomes?

A. a p-type semiconductor B. an n-type semiconductor C. an insulator D. an intrinsic semi-conductor Correct Answer: Option B -…

4 years ago

Which of the following can conduct electricity owing to the presence of free mobile electrons?

A. germanium B. silicon C. grapefruit D. copper Correct Answer: Option D = copper Explanation Metals are good conductors due…

4 years ago

Thermionic emission is the process whereby?

A. β - rays are produced B. holes are produced C. x - rays are produced D. electrons leave a…

4 years ago

If the decay constant of a radioactive substance is 0.231s¹; the half-life is?

A. 3.00 s B. 0.12 s C. 0.33 s D. 1.50 s Correct Answer: Option A = 3.00 s Explanation…

4 years ago

Cancerous cells can be destroyed by?

A. ultraviolet rays B. alpha particles C. x - rays D. infrared rays Correct Answer: Option C = x-rays Explanation…

4 years ago