Answer:
19 cm sq
Explanation:
you have to count one full and half area occupied by leaf in each box, then you have to multiply with 1 cm sq.
Answer:
Question 1)
a) The speed of the drums is increased from 2 ft/s to 4 ft/s in 4 s. From the below kinematic equations the acceleration of the drums can be determined.

This is the linear acceleration of the drums. Since the tape does not slip on the drums, by the rule of rolling without slipping,

where α is the angular acceleration.
In order to continue this question, the radius of the drums should be given.
Let us denote the radius of the drums as R, the angular acceleration of drum B is
α = 0.5/R.
b) The distance travelled by the drums can be found by the following kinematics formula:

One revolution is equal to the circumference of the drum. So, total number of revolutions is

Question 2)
a) In a rocket propulsion question, the acceleration of the rocket can be found by the following formula:

b) 
Answer: 4.45m/s
Explanation:
I assume we're solving for her speed.
400m x 4 laps = 1600m
1600m / 6 minutes = 266.67m/min
(266.67m/min) x (1 minute/60 seconds) = 4.45m/s
266.67/60 = 4.45m/s
I halved the speed of light in vacuum to get the speed of light in the material, since the speed of light in vacuum is twice the speed of light in material.
The index of refraction is essentially the speed of light through a vacuum divided by the speed of light through given medium.
I attached some notes on refraction too, hopefully this helps :D
Answer: I don't know spanish
Explanation: