BMST Newton's Laws of Motion 2

Question 1

A 10 kg box is pushed with a net force of 30 N. What is the acceleration of the box?

Accepted Answer

3 m/s²

Answer

Newton's second law: a = F/m = 30 N / 10 kg = 3 m/s².

Question 2

Which of Newton's laws explains why passengers lurch forward when a car suddenly brakes?

Accepted Answer

Newton's First Law

Answer

Newton's First Law states objects in motion stay in motion; passengers continue moving forward when the car stops.

Question 3

A rocket expels gas downward to propel itself upward. This is best explained by:

Accepted Answer

Newton's Third Law

Answer

Newton's Third Law: the rocket pushes gas down, and the gas pushes the rocket up with an equal and opposite force.

Question 4

If the mass of an object doubles while the net force stays the same, the acceleration will:

Accepted Answer

Halve

Answer

Since a = F/m, doubling mass with constant force cuts acceleration in half.

Question 5

An object sitting on a table remains at rest. According to Newton's First Law, this means:

Accepted Answer

The net force on it is zero

Answer

An object at rest has balanced (zero net) forces; gravity and the normal force cancel each other.

BMST - Basic Math and Science Test Practice Test