Kinematics

Question 1

An apple falls from the tree, and after 0.8 s it lands on the head of a man sleeping under a tree. Let us assume that the apple’s motion was free fall.

A) the velocity at time of impact (in km/h)

B) how high was the branch from the man’s head?

Answer 1

A) v= a * t
a = 9.81 m/s
t= 0.8 s

9. 81 * 0.8 = 7.8 m/s.
10. 8 m/s * 3.6 = 28.08 km/h.

B) Distance travelled:

The velocity increases linearly with time.

V (average) = v0 + v/2.

v0 + 7.8 m/s/2 = 3.9 m/s.

S= v(average) * t = 3.12 m.

Question 2

Period?

Definition, formula and SI unit

Answer 2

The duration of one cycle in a repeating event.

1/F (s)

Question 3

Frequency:

Definition, formula and SI unit

Answer 3

Number of occurrences of a repeating event.

1/T (Hz)

Question 4

Angular velocity (formula and SI unit)

Answer 4

W = 2pi * f (1/s)

Question 5

Velocity: formula and SI unit

Answer 5

V = a * t Or V= r * angular velocity (m/s)

Question 6

Is the gravitation the same everywhere?

Answer 6

No, is it greater by equator and smaller at poles.

Question 7

How do you calculate the distance travelled?

Answer 7

S = average velocity * t.

Question 8

When is the acceleration of a body when the velocity is constant?

Answer 8

0

Question 9

What is the formula for uniform circular motion?

Answer 9

‘’’y’’’= angular frequency/velocity (w) *t