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3 years ago

Physical changes (2 points)

1 answer:

5 0

Physical changes do not change the identity of the substance. Heat causes chemical reactions. You cannot see chemical changes with the naked eye. The identity of a substance changes like when you burn paper, from paper it turns into ash and produces smoke, which are products from the chemical reactions.

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1) A sound wave with a frequency of 300 hertz is traveling through a medium at a speed of 320 meters/second. What is its wavelen

timurjin [86]

1. The wavelength is the ratio of the wave's speed to its frequency in hertz or 1/s. This is shown below,
λ = s / f = (320 m/s) / (300 1/s) = 1.07 m
The wavelength is approximately 1.07 m.

2. The frequency is the ratio between speed and the wavelength,
f = (330 m/s) / 0.45 m = 733.33 hertz

5 0

3 years ago

Read 2 more answers

Paco was driving his scooter west with an initial velocity of 4 m/s. He accelerates at 0.5 m/s2 for 30 seconds.

KonstantinChe [14]

Answer:

V = 19m/s

Explanation:

Given the following data;

Initial velocity, U = 4m/s

Acceleration, a = 0.5m/s²

Time, t = 30 seconds

To find the final velocity, we would use the first equation of motion;

V = U + at

Where;

V is the final velocity.

U is the initial velocity.

a is the acceleration.

t is the time measured in seconds.

V = 4 + 0.5*30

V = 4 + 15

V = 19m/s

Therefore, his final velocity is 19 meters per seconds.

6 0

3 years ago

Read 2 more answers

A car is traveling at 114 m/s and changes its velocity to 77 m/s in 9 sec.

suter [353]

Answer:

Given -

Initial Velocity, u = 114 m/s
Final velocity, v = 77 m/s.
Time taken, t = 9 sec.

To find - 

Acceleration of the car.

Solution -

Here, using the equation of motion v = u + at we can find the acceleration easily.

★ Here,

V = Final velocity
U = Initial Velocity
A = Acceleration
T = Time.

Substituting the values -

→ 77 = 114 + a(9)

→ 9a = 114 - 77

→ 9a = 37

→ a = 37/9

→ a = 4.1 m/s

Therefore, the acceleration of the car will be 4.1 m/s.

5 0

3 years ago

Write Newton's 3rd law. How would this law relate to a rocket ship taking off from the earth? Would this law affect the rocket s

irina1246 [14]

Answer:

Part A

Newton's 3rd law states that action and reaction are equal and opposite, mathematically, we have;

$F_A$ = - $F_B$

Where;

$F_A$ = The action force

$F_B$ = The reaction force

Part B

The law indicates that the force with which a rocket ship uses in taking off from the Earth, $F_A$ is equal in magnitude, and opposite in direction to the reaction force of the Earth to the motion of the rocket, (-) $F_B$

Part C

The law is a universal law, and it will also affect the rocket ship in space, as the force of the jet from the exhaust is directed towards Earth while in space, the rocket is propelled deeper into space

Explanation:

6 0

3 years ago

A body accelerate uniformly from rest at the rate of 3meters per seconds for 8 sec . calculate the distance covered by the body

pishuonlain [190]

Answer:

96 m

Explanation:

Given:

v₀ = 0 m/s

a = 3 m/s²

t = 8 s

Find: Δx

Δx = v₀ t + ½ at²

Δx = (0 m/s) (8 s) + ½ (3 m/s²) (8 s)²

Δx = 96 m

3 0

3 years ago