Ask question

Ask question

All categories

2 years ago

10

If a firework has an initial velocity of 235m/s and is in the air for 12 seconds with an acceleration of -10 m/s2 before explodi

ng, how far did it go?

1 answer:

azamat2 years ago

6 0

Answer:

$\boxed {\boxed {\sf 2100 \ meters}}$

Explanation:

We are asked to find the distance a firework travels.

We are given the initial velocity, acceleration, and time, but we don't know the final velocity. Therefore, we will use the following kinematic equation.

$d=v_it+\frac{1}{2} at^2$

The initial velocity is 235 meters per second. The firework travels for 12 seconds. It has an acceleration of -10 meters per second squared.

$v_i$ = 235 m/s
t= 12 s
a= -10 m/s²

Substitute the values into the formula.

$d= (235 \ m/s)(12 \ s) + \frac{1}{2} (-10 m/s^2)(12 \ s)^2$

Multiply the first 2 numbers in parentheses. The units of seconds cancel.

$d=(235 \ m * 12 ) + \frac{1}{2} (-10 \ m/s^2)(12 \ s )^2$

$d= (2820 \ m)+ \frac{1}{2} (-10 \ m/s^2)(12 \ s )^2$

Solve the exponent.

(12 s)²= 12 s * 12s = 144 s²

$d=(2820 \ m)+ \frac{1}{2} (-10 \ m/s^2)(144 \ s^2)$

Multiply the other numbers in parentheses. The units of seconds squared cancel.

$d=(2820 \ m)+ \frac{1}{2} (-10 \ m * 144 )$

$d=(2820 \ m)+ \frac{1}{2} (-1440 \ m)$

Multiply by 1/2 or divide by 2.

$d= 2820 \ m + (-720 \ m)$

Add.

$d= 2100 \ m$

The firework traveled <u>2100 meters</u> before exploding.

You might be interested in

In many cartoon shows, a character runs of a cliff, realizes his predicament and lets out a scream. He continues to scream as he

Amanda [17]

Answer:D

Explanation:

When the character falls off from cliff he moves away from the observer as he falls down and hence the frequency heard by observer lowers as he falls.

Therefore the pitch of the sound is lower than the original sound and decreasing as he falls

Option D is the correct choice

7 0

3 years ago

How much energy has 4×10^10m^3 of water collected in a reservoir at a hight of 100 m from the power house ?What kind of energy i

sveticcg [70]

Answer:

PE = 3.92x10^16J

potential energy

Explanation:

PE = m*g*h

mass of water = 1000kg/m³

(4*10^10m³)*1000kg = 4*10^13kg

PE = (4*10^13kg)*(9.81m/s²)*(100m)

PE = 3.92x10^16J

7 0

3 years ago

The parallel axis theorem relates Icm, the moment of inertia of an object about an axis passing through its center of mass, to I

erma4kov [3.2K]

Answer:

Part a)

$I_{end} = \frac{mL^2}{3}$

Part b)

$I_{edge} = \frac{2ma^2}{3}$

Explanation:

As we know that by parallel axis theorem we will have

$I_p = I_{cm} + Md^2$

Part a)

here we know that for a stick the moment of inertia for an axis passing through its COM is given as

$I = \frac{mL^2}{12}$

now if we need to find the inertia from its end then we will have

$I_{end} = I_{cm} + Md^2$

$I_{end} = \frac{mL^2}{12} + m(\frac{L}{2})^2$

$I_{end} = \frac{mL^2}{3}$

Part b)

here we know that for a cube the moment of inertia for an axis passing through its COM is given as

$I = \frac{ma^2}{6}$

now if we need to find the inertia about an axis passing through its edge

$I_{edge} = I_{cm} + Md^2$

$I_{edge} = \frac{ma^2}{6} + m(\frac{a}{\sqrt2})^2$

$I_{edge} = \frac{2ma^2}{3}$

7 0

3 years ago

This is a group of elements with few valence electrons that conducts heat and electricity.

k0ka [10]

Answer:

Metals

Explanation:

The group of elements with few valence electrons that conducts heat and electricity is known metals. Metals are good conductors of heat and electricity. The outer electrons in metals are loosely bound to the atom and are thus able to freely move around and conduct electricity and heat.

5 0

3 years ago

If a wave has amplitude of 2 meters, a wavelength of 5 meters, and a frequency of 60 Hz, at what speed is it moving?

klemol [59]

The relationship between speed of a wave w, frequency f and wavelength $\lambda$ is
$v = \lambda f$
For the wave of our problem, $\lambda = 5 m$ and f=60 Hz, so its speed is
$v=(5 m)(60 Hz)=300 m/s$

5 0

3 years ago

Read 2 more answers