Newton Mechanics

Question 1

Acceleration, a

Answer 1

The rate of change of velocity with respect to time.

Question 2

Newton’s First Law

Answer 2

A body stays at restcor continues to movr with a constant speed in a straight line unless a net external force acts on it.

Question 3

Newton’s Second Law

Answer 3

The rate of change of momentum of a body is proportional to the resultant force acting on it and occurs in the direction of the force.

Question 4

Newton’s Third Law

Answer 4

If body A exerts a force on body B, then body B exerts an equal but opposite force on body A.

Question 5

Linear Momentum

Answer 5

The product of the mass of an object and its velocity.

p=mv

Question 6

Impulse

Answer 6

Impulse of a force is the product of the average force and the time interval over which it is applied.
J=F dt =dp
Impulse is the area under the force-time graph.

Question 7

Force, F

Answer 7

The rate of change of momentum.

Question 8

Principle of Conservation of Momentum

Answer 8

The total linear momentum of a system remains unchanged if no net external force acts on the system.

Question 9

Couple

Answer 9

A couple consists of a pair of parallel forces of equal magnitude but opposite direction whose lines of action do not coincide.

Question 10

Moment of a Force

Answer 10

The moment of a force about a point is the product of the force with the perpendicular distance of the force from that point.

Question 11

Torque of a Couple, τ

Answer 11

The torque of a couple is the product of one of the forces with the perpendicular separation between the couple.

Question 12

Head-on collision

Answer 12

A type of collision in which the directions of motion before and after the collisiom are along the same line of motion.

Question 13

RSOA RSOS

Answer 13

For elastic collion, RSOA=RSOS
u1-u2=v2-v1
(take note of sign convention, assume known velocity is positive)
100% KE is conserved!

Question 14

Same final velocity

Answer 14

Perfectly inelastic collision

Use one variable v to represent the final velocity

Question 15

Condition for translational equilibrium

Answer 15

The net external force acting on the body is zero.

Question 16

Moment of a force

Answer 16

The moment of a force about a point is the product of the force and the perpendicular distance of the line of action of the force to the point.

Question 17

Condition for rotational equilibrium

Answer 17

The net moment on the body about any point is zero

Question 18

Principle of moments

Answer 18

For a body to be in rotational equilibrium,

Sum of CWM about any point= Sum of ACWM about the same point

Question 19

Conditions for static equilibrium

Answer 19

The net external force acting on the body us zero.

The net torque on the body about any point is zero

Question 20

Three-force system

Answer 20

When an object is in equilibrium, all the 3 forces acting on the object should intersect at a common point

Question 21

Couple

Answer 21

A pair of forces which are equal inmagnitude but opposite in direction, whose lines of action do not coincide.

Question 22

Torque of a couple

Answer 22

Is tge product if tge perpendicular distance between the lines of action of the forces and the magnitude of one if the forces.

Question 23

Principle of floatation

Answer 23

Weight of fluid displaced= weight of the obejct

ps Upthust = weight of the fluid displaced, when the body is floating, then U=W of liquid displaced=W of object

Question 24

Upthrust

Answer 24

Net upward dorce exerted by a fluid on a body fully or partially submerged in the fluid