Help pls ... will give brainlist

How to find displacement with velocity and time?

butalik [34]

Displacement = velocity * time

Just substitute the value, & solve the equation.

Hope this helps!

4 0

3 years ago

An aquarium open at the top has 30-cm-deep water in it. You shine a laser pointer into the top opening so it is incident on the

Setler [38]

Answer:

You must add 8cm of water to the tank

Explanation:

In order to find how much the height is we will use the Snell Refraction law

.

This law relates the index of refraction of the water (n2), the index of refraction of the air (n1), the incidence angle relative to the vertical (theta1) and the refraction angle relative to the vertical (theta2) by using the next equation:

$(n1)*(sin(theta1))=(n2)*(sin(theta2))$

Then we will find the refraction angle relative to the vertical this way:

$(n1/n2)*(sin(theta1))=sin(theta2)$

$(1/1.33)*(sin(45))=sin(theta2)$

Then, theta2=32.12°

Now that we have this information we can imagine a triangle with a 30cm height and a 32.12° angle. This way we can find how much X is, this X will be the distance between the vertical line and the spot the beam hits the bottom, so we can use some trigonometry to find it, this way:

$tan(32.12)=(X/30cm)$

$X=(tan(32.12))*(30cm)$

Then, X=18.8cm, we can approximate it to 19cm

Once we have X we will add 5cm to it which is how much the beam needs to be moved, then the new X will be 24cm

Now, with the new horizontal distance we will find the new vertical distance, let´s call it Y, this way we will know how much water we must add to move the beam, then we will have a triangle with a vertical distance called Y, the same 32.12° angle will be used as we are still working with the air-water interface and a 19cm horizontal distance, then:

$tan(32.12)=(24cm/Y)$

$Y=(24cm/tan(32.12))$

Then, Y=38cm

In this case, you must add 8cm of water to the tank to move the beam on the bottom 5cm

5 0

3 years ago

The engine in an imaginary sports car can provide constant power to the wheels over a range of speeds from 0 to 70 miles per hou

kirill115 [55]

Answer:

Part A

it would take 6 sec

it would take 3 sec

Explanation:

We are told that the power supplied to the wheel is constant which means that the sport car is gaining energy i.e

$power \ \alpha \ energy$

Hence if power is constantly supplied energy constantly increase

From the formula of the Kinetic energy

$KE = \frac{1}{2} mv^2$

we can see that as the speed doubles from 29 mph to 58 mph the energy needed is $2^2$ = 4 times of the energy from the formula

Also the time needed would also be 4 times because energy i directly proportional to time

Hence to reach 58mph the time that it would take is

= $4* 1.5sec = 6sec$

We are told that the ground pushes the car with a constant force and

F = ma

this means that the acceleration is also constant

now from newtons law

v = u +at

Looking at it we see that final velocity is directly proportional with time

hence it would take twice the time to reach twice the final velocity

Time to reach 58mph = 3 s

since time to reach 29 mph( $\frac{1}{2} \ of \ [58mph]$ ) =( $\frac{1}{2} \ of \ 3sec$ )1.5 s

6 0

3 years ago

Which of the following best describes a magnet?

12345 [234]

C
Because magnet involves 2 opposite poles so therefore it would have to be C

8 0

3 years ago

Read 2 more answers

What are two different ways to understand time? Explain and give examples.

Maru [420]

There are two different ways to understand time and these are:
A. What time is it?
B. How much time?
The examples of these two different ways are:
A. What time is it? The best example that would help us understand and know what time are the clock and the calendar. This gives us the exact hour, minutes and seconds. The calendar tells us the exact day, month and year.
B. How much time? This makes us understand how much time did it take from the starting time. An example for this would be a stopwatch.

6 0

3 years ago