A projectile is to be launched at an angle of 30° so that it falls beyond the pond of length 20 meters as shown in the figure.

You biked to the store in 10 minutes. The store was 3 km away. What was your average speed?

sineoko [7]

Answer:

speed in km/min:

0.3km/min

speed in km/h:

18km/h

speed in m/s:

5m/s

Explanation:

the average speed is defined as:

$s=\frac{d}{t}$

where $s$ is the speed, $d$ is the distance traveled, and $t$ is the time

according to the statement:

$d=3km = 3,000m$

and

$t=10min=\frac{1}{6}h=600s$ (10 minutes are equal to a sixth of an hour which is 600 seconds)

Because the units in which the speed is required are not indicated, here are some options for the answer:

Depending on the units in which you need the speed, are the quantities you should use.

Speed in km / h (kilometers per hour):

$s=\frac{3km}{\frac{1}{6}h }\\ \\s=18km/h$

speed in m / s (meters per second):

$s=\frac{3,000m}{600s}\\ s=5m/s$

or the speed in km/min (kilometers per minute)

$s=\frac{3km}{10min}\\ s=0.3km/min$

4 0

3 years ago

Describe how we know the plates once formed a supercontinent and how we know this.

Lady_Fox [76]

Answer:

<h3>How did scientists “discover” Pangea and other supercontinents of the past?</h3>

Nowadays, they can study the geologic record and use radioactive dating, seismic surveys, and other technologies to construct maps of how the world looked at various points in Earth's history.

3 0

2 years ago

You are conducting an experiment inside a train car that may move along level rail tracks. A load is hung from the ceiling on a

katrin2010 [14]

Answer:

b

c

e

h

Explanation:

Note that the swing direction was not giving in the question and direction could be sideways (in a turn) or in a track or both

The question show something in common ...acceleration

So let's look at the statements and pick the correct ones

a is false while b is correct as the train is accelerating

c is correct. The train is accelerating even thou the speed could not be ascertained

d is false and not feasible as the train is accelerating

e is true as the train maybe moving at a constant speed in a circle

f is false. This could be constant velocity in a circle. Same as g (false)

h is true. It's accelerating

7 0

3 years ago

The carbon atom with 12 protons and 12 electrons has a charge of:

olga55 [171]

Answer:

Isotopes are the elements having the same atomic number i.e same number of protons which in turn is equal to same number of electrons. Number of protons and electrons are equal as the atom is electrically neutral. So, the only option is A.

I hope it helps you !

3 0

2 years ago

What is the impulse of a 3 kg object that starts from rest and moves to 20 m/s?

IrinaK [193]

Answer:

The impulse on the object is 60Ns.

Explanation:

Impulse is defined as the product of the force applied on an object and the time at which it acts. It is also the change in the momentum of a body.

F = m a

F = m( $\frac{v_{2} - v_{1} }{t}$ )

⇒ Ft = m( $v_{2}$ - $v_{1}$ )

where: F is the dorce on the object, t is the time at which it acts, m is the mass of the object, $v_{1}$ is its initialvelocity and $v_{2}$ is the final velocity of the object.

Therefore,

impulse = Ft = m( $v_{2}$ - $v_{1}$ )

From the question, m = 3kg, $v_{1}$ = 0m/s and $v_{2}$ = 20m/s.

So that,

Impulse = 3 (20 - 0)

= 3(20)

= 60Ns

The impulse on the object is 60Ns.

8 0

2 years ago