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3 years ago

Will mark brainliest if correct!!!!!!!!!!!

Physics

2 answers:

Setler79 [48]3 years ago

8 0

Answer:

bouncing off a surface

Explanation:

definition of reflection: the throwing back by a body or surface of light, heat, or sound without absorbing it.

kogti [31]3 years ago

3 0

Answer:

Explanation:

Reflect: (of a surface or body) throw back (heat, light, or sound) without absorbing it.

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A stone is thrown with an initial speed of 11.5 m/s at an angle of 50.0 above the horizontal from the top of a 30.0-m-tall build

rewona [7]

Answer:

The magnitude of the horizontal displacement of the rock is 7.39 m/s.

Explanation:

Given that,

Initial speed = 11.5 m/s

Angle = 50.0

Height = 30.0 m

We need to calculate the horizontal displacement of the rock

Using formula of horizontal component

$v_{x}=u\cos\theta$

Put the value into the formula

$v_{x}=11.5\times\cos50$

$v_{x}=7.39\ m/s$

Hence, The magnitude of the horizontal displacement of the rock is 7.39 m/s.

8 0

3 years ago

An engine extracts 441.3kJ of heat from the burning of fuel each cycle, but rejects 259.8 kJ of heat (exhaust, friction,etc) dur

Lilit [14]

Answer:

The thermal efficiency is 0.4113.

Explanation:

We know that the thermal efficiency is the ratio of work done by the engine over the heat taken

$\eta = \frac{W_{made}}{Q_{in}}$

Now, how much work the engine do in a cycle?

We know that the work done in a cycle must be equal to the heat taken minus the heat rejected

$W{made} = Q_{in} - Q_{rejected}$

So, the thermal efficiency will be:

$\eta = \frac{Q_{in} - Q_{rejected}}{Q_{in}}$

$\eta = \frac{Q_{in}}{Q_{in}} - \frac{Q_{rejected}}{Q_{in}}$

$\eta = 1 - \frac{Q_{rejected}}{Q_{in}}$

Putting the values of the problem

$\eta = 1 - \frac{259.8 kJ }{441.3kJ}$

$\eta = 0.4113$

7 0

4 years ago

A ball was rolling downhill at 2 m/s. After 5s, it was rolling at 90 m/s. What is its acceleration?

olga55 [171]

Answer:

17.6 m/s²

Explanation:

Given:

$v_{f}$ = 90 m/s (final velocity)

$v_{i}$ = 2 m/s (initial velocity)

Δt = 5s (change in time)

The formula for acceleration is:

$a_{avg}$ = Δv / Δt

We can find Δv by doing

Δv = $v_{f}$ - $v_{i}$

Replace the values

Δv = 90m/s - 2m/s

Δv= 88m/s

Using the equation from earlier, we can find the acceleration by dividing the average velocity by time.

$a_{avg}$ = Δv / Δt

$a_{avg}$ = $\frac{88m/s}{5/s}$

acceleration = 17.6 $m/s^{2}$

4 0

3 years ago

Question 6

Kisachek [45]

6. gas

7. liquid

8. gas

9. does not change

10. boiling point

7 0

3 years ago

1. A drop of oil of volume 10-10 m spreads out on water to

ankoles [38]

Answer:

318.3 nm

Explanation:

We approximate the circular film as a cylinder of height h and radius, r. Its volume V = πr²h. Since this volume equals the volume of the oil drop, the height of the circular film is thus h = V/πr²

V = 10⁻¹⁰ m³ and r = 10 m

Substituting into h, we have

h = 10⁻¹⁰ m³/π(10)²

= 0.3183 × 10⁻¹² m

= 3183 × 10⁻⁹ m

= 318.3 nm

5 0

3 years ago