Answer:
12.74 ms^-1 download
Explanation:
v=28.2, a=9.81
start from rest u=0
v=u+at=0+(9.81)t=28.2
t=2.875...
it reach 1.4 second before hitting the ground:
t=1.4, u=0, a=9.81
v=u+at=0+(9.81)(1.4)=12.74
Answer:
The magnitude of the net electric field is:

Explanation:
The electric field due to q1 is a vertical positive vector toward q1 (we will call it E1).
On the other hand, the electric field due to q2 is a horizontal positive vector toward q2(We will call it E2).
Knowing this, the <u>magnitude of the net electric</u> field will be the<u> E1 + E2. </u>
Let's find first E1 and E2.
The electric field equation is given by:

Where:
- k is the Coulomb constant (k = 9*10^{9} Nm²/C²)
- q1 is the first charge
- d1 is the distance from q1 to P


And E2 will be:



Finally, we need to use the Pythagoras theorem to find the magnitude of the net electric field.



I hope it helps you!
Answer:
1.31498 kg
0.72050 s
0.72050 s
Explanation:
m = Mass of block
g = Acceleration due to gravity = 9.81 m/s²
k = Spring constant = 100 N/M
x = Displacement = 0.129 m
The force balance is

The mass of the block is 1.31498 kg
Time period is given by

The period of oscillations is 0.72050 s
The time period does not depend on the acceleration due to gravity. It varies with the mass and the spring constant.
Hence, the time period would be the same
Answer:

The rule for kilometers is that every three seconds between a lightning flash and the following thunder gives the distance to the flash in kilometers.
Explanation:
In order to use the rule of thumb to find the speed of sound in meters per second, we need to use some conversion ratios. We know there is 1 mile per every 5 seconds after the lightning is seen. We also know that there are 5280ft in 1 mile and we also know that there are 0.3048m in 1ft. This is enough information to solve this problem. We set our conversion ratios like this:

notice how the ratios were written in such a way that the units got cancelled when calculating them. Notice that in one ratio the miles were on the numerator of the fraction while on the other they were on the denominator, which allows us to cancel them. The same happened with the feet.
The problem asks us to express the answer to one significant figure so the speed of sound rounds to 300m/s.
For the second part of the problem we need to use conversions again. This time we will write our ratios backwards and take into account that there are 1000m to 1 km, so we get:

This means that for every 3.11s there will be a distance of 1km from the place where the lightning stroke. Since this is a rule of thumb, we round to the nearest integer for the calculations to be made easily, so the rule goes like this:
The rule for kilometers is that every three seconds between a lightning flash and the following thunder gives the distance to the flash in kilometers.
Answer:
A. cell walls
Explanation:
Plants have cell walls but animals dont.