A plate glass window (n = 1.5 has a thickness of 3.6 mm. how long does it take light to pass perpendicularly through the plate?

A hummingbird’s wings beat 100 times in 5 seconds. What is the frequency?

Sonbull [250]

20 beats per second.

Explanation: 20 x 5 =100

6 0

2 years ago

A ball at rest rolls across a frictionless floor at 12.0 m/s/s. How far will it travel in

professor190 [17]

Answer:

The distance, d travelled by the ball is 768 metres.

Explanation:

In physics, acceleration can be defined as the rate of change of the velocity of an object with respect to time.

This simply means that, acceleration is given by the subtraction of final speed from the initial speed all over time.

Hence, if we subtract the final speed from the initial speed and divide that by the time, we can calculate an object’s acceleration.

Mathematically, acceleration is given by the equation;

$Acceleration (a) = \frac{initial \; speed - final \; speed}{time}$

$a = \frac{v - u}{t}$

Where,

a is acceleration measured in $ms^{-2}$

v and u is initial and final speed respectively, measured in $ms^{-1}$

t is time measured in seconds.

Given the following data;

Acceleration = 12.0m/s²

Time, t = 8secs

Velocity =?

First, we would calculate its velocity;

$a = \frac{v - u}{t}$

Since the ball rolls at rest, initial velocity is zero (0).

$V = a * t$

$V = 12 * 8$

$Velocity = 96ms^{-1}$

We can now solve for the distance;

$Velocity = \frac{distance}{time}$

Therefore,

$Distance = velocity * time$

$Distance = 96 * 8$

Distance = 768m.

3 0

3 years ago

A paper airplane has an acceleration of 5 m/s^2. If it is thrown from rest (0 m/s), how fast will it be going in 3 seconds?

FinnZ [79.3K]

Answer: its 0 i guess

Explanation:

7 0

3 years ago

What formula do I use for the second question? For number 3 how is one energy converted to the other? ( using arrows ) I get num

Fed [463]

#2
Use the formula ... Kinetic energy = (1/2) x (mass) x (speed)²

#3 - a).
sun => energy travels as electromagnetic waves => reaches Earth as
 heat & light energy.

sun => absorbed in plants => eaten by animals => animals die =>
 decay into oil in millions of years => we burn the oil to get the energy.

#3 - b).
food I ate for lunch => metabolized into glucose by my body
 => some of it burned in my muscles to generate energy for immediate needs
 => the rest of it stored as fat for future needs.

#3 - c).
flower pot rolls off the ledge => gravity does work on it all the way down,
 producing the kinetic energy it has when it hits the floor.

#3 - d).
oil or natural gas is burned, releasing heat energy => energy is used
 to generate electricity => electricity flows through cables from the
 power generating plant to your home => hot plate plugged into the
 wall => turns electrical energy back into heat energy => heat energy
 is conducted into the bottom of the beaker, flows through the glass
 to the inside surface => heat energy is conducted from the inside of
 the glass to the water, which gets hotter as it absorbs more energy.
=============================

Note:
#1 on the sheet is wrong.
"Work = force x distance" that's correct
But 25-kg is the mass of the ball, not the gravitational force on it.
The force on it is (mass) x (gravity), called its "weight".
 That's (25-kg) x (9.8 m/s²) = 245 kg-m/s² = 245 newtons .

6 0

3 years ago

The bell rings and a physics student heads to class. They stop to talk to a few friends. They slow

grin007 [14]

Answer:

420m

Explanation:

Given parameters:

Time = 5minutes

Average speed = 1.4m/s

Unknown:

Distance covered = ?

Solution:

Speed is the rate of change of distance with time.

Mathematically;

Speed = $\frac{distance}{time}$

Distance = speed x time

Insert the parameters and solve;

Convert the time to seconds;

1 minute = 60s

5 minute = 5 x 60 = 300s

So,

Insert the parameters and find the distance;

Distance = 300 x 1.4 = 420m

3 0

3 years ago