Motion

Question 1

What is Newton’s first law?

Answer 1

“A body remains at rest or in a state of uniform motion in a straight line unless it is acted on by an applied force.”

Question 2

What is Newton’s second law?

Answer 2

“The time rate of change of the linear momentum of a body is equal to the force F applied to it.”

Question 3

How is Newton’s second law expressed in mathematical terms?

Answer 3

F = ma
Force = mass x acceleration

Question 4

What is Newton’s third law?

Answer 4

“For every action, there is an equal and opposite reaction.”

Question 5

What is translational motion?

Answer 5

The motion of a body in which all parts of the body have the same velocity and acceleration.

Question 6

What is pure rotational motion?

Answer 6

Motion in which the rate of change in the angle is the same for all parts of the body but the velocity and acceleration along the body depend on the distance from the centre of rotation.

Question 7

What forces are acting on a jumper during vertical jump?

Answer 7

Weight of the jumper (W) which is the downward force and the reaction force (F) which id the upward motion.

Question 8

How is the net upward on the jumper expressed?

Answer 8

F - W

Question 9

How is the acceleration of the jumper expressed mathematically?

Answer 9

a = F - W/(W/g)
W = weight of jumper
g = gravitational acceleration

Question 10

What is the equation for calculating height of the jump?

Answer 10

H = (F-W)c/W

Question 11

What is the velocity at the full height of the jump?

Answer 11

Zero

Question 12

What is the weight of an object dependent on?

Answer 12

The mass and size of the planet on which it is located.

Question 13

What is metabolic rate?

Answer 13

The energy consumed per unit time.

Question 14

How is work done during a vertical jump calculated?

Answer 14

Weight x height of jump

Question 15

What is the simplest angular motion?

Answer 15

One in which the body moves along a curved path at a constant angular velocity.

Question 16

When would a car begin to skid?

Answer 16

When the centrifugal force is greater than the frictional force.

Question 17

What forces act on the foot of a runner?

Answer 17

An upward force which supports the athletes weight and a centrifugal force which counteracts the centrifugal force.

Question 18

When would a car begin to skid?

Answer 18

When the centrifugal force is greater than the frictional force.

Question 19

What forces act on the foot of a runner?

Answer 19

An upward force which supports the athletes weight and a centrifugal force which counteracts the centrifugal force.

Question 20

What is the back and forth movement of a pendulum called?

Answer 20

Harmonic movement.

Question 21

What is the number of times the pendulum swings back and forth called?

Answer 21

The frequency.

Question 22

What is the period of a pendulum?

Answer 22

The time for completing one cycle of the motion.

Question 23

When is a pendulum’s energy entirely potential?

Answer 23

At the extreme of the swing

Question 24

What happens to the energy of a pendulum as it is accelerated towards the centre?

Answer 24

Its velocity increases and the potential energy is converted to kinetic energy.

Question 25

When is the velocity of a pendulum at its maximum?

Answer 25

When the pendulum passes the centre position.

Question 26

When is a pendulum’s energy entirely kinetic?

Answer 26

When it passes the centre point.

Question 27

What is the gravitational acceleration on Earth?

Answer 27

9.8 m/sec^2

Question 28

How is gravitational force calculated?

Answer 28

F = mg 
g = gravitational acceleration