EmSAT Physics 3

Question 1

A ball is thrown horizontally from the top of a 45 m cliff with a speed of 20 m/s. How far from the base of the cliff does it land? (g = 10 m/s²)

Accepted Answer

60 m

Answer

Time to fall: t = √(2h/g) = √9 = 3 s; horizontal range = 20 × 3 = 60 m.

Question 2

A 2 kg object moves in a circle of radius 0.5 m at a speed of 4 m/s. What is the centripetal force acting on it?

Accepted Answer

32 N

Answer

F = mv²/r = 2 × 16 / 0.5 = 64 N — wait, that gives 64 N; recalculating: 2 × 16 / 0.5 = 64 N.

Question 3

Which of the following correctly describes the relationship between pressure and depth in a static fluid?

Accepted Answer

Pressure increases linearly with depth

Answer

Hydrostatic pressure P = ρgh increases linearly with depth h.

Question 4

A spring with spring constant 200 N/m is compressed by 0.1 m. What is the elastic potential energy stored?

Accepted Answer

1 J

Answer

E = ½kx² = ½ × 200 × 0.01 = 1 J.

Question 5

Two charges of +3 μC and –3 μC are placed 0.3 m apart. The electrostatic force between them is best described as:

Accepted Answer

Attractive

Answer

Opposite charges attract, so the force is attractive; unlike charges always attract regardless of magnitude.

EmSAT Practice Test