Forces and Motion Principles Questions and Answers Flashcards
6 cards from real MECHANICAL APTITUDE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Forces and Motion Principles Questions and Answers flashcards as text
A 5 kg object is accelerating at 3 m/s². What is the net force acting on it?
Answer: 15 N
Using Newton's Second Law (F = ma): F = 5 kg × 3 m/s² = 15 N. The net force acting on the object is 15 Newtons.
What is the term for the tendency of an object to resist changes in its state of motion?
Answer: Inertia
Inertia is the property of matter that resists changes in motion. An object at rest tends to stay at rest, and an object in motion tends to stay in motion at constant velocity, unless acted upon by an external force (Newton's First Law).
When two objects collide and stick together, what type of collision has occurred?
Answer: Inelastic collision
When objects collide and stick together, it is a perfectly inelastic collision. In this type, momentum is conserved but kinetic energy is not — some is converted to heat, sound, and deformation. This is the maximum loss of kinetic energy possible in a collision.
An object is thrown straight up into the air. At the highest point of its trajectory, what is its velocity?
Answer: Zero
At the highest point, the object momentarily stops before falling back down, so its velocity is zero. Gravity decelerates the object on the way up and accelerates it on the way down.
What is the relationship between action and reaction forces according to Newton's Third Law?
Answer: They are equal in magnitude and opposite in direction
Newton's Third Law states that for every action, there is an equal and opposite reaction. These forces are equal in magnitude but opposite in direction, and they always act on different objects.
A car traveling at 60 km/h has how much kinetic energy compared to the same car at 30 km/h?
Answer: Four times as much
Kinetic energy is proportional to the square of velocity (KE = ½mv²). Doubling the speed from 30 to 60 km/h means the kinetic energy increases by a factor of (60/30)² = 4.