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3 years ago

Which statement is a scientific law?

Physics

2 answers:

gavmur [86]3 years ago

6 0

a. Scientists use genes to explain why evolution works

oksian1 [2.3K]3 years ago

4 0

A. because it's been repeated multiple times

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During a medieval siege of a castle, the attacking army uses a trebuchet to heavy stones at the castle the trebuchet launches th

vlada-n [284]

Answer:

Explanation:

The question relates to time of flight of a projectile .

Time of flight = 2 u sinθ / g

u is speed of projectile , θ is angle of projectile

= 2 x 48.5 sin42 / 9.8

= 6.6 seconds .

Maximum height attained

= u² sin²θ / g

= 48.5² sin²42 / 9.8

= 107.47 m .

7 0

3 years ago

A generator uses a coil that has 100 turns and a 0.50-T magnetic field. The frequency of this generator is 60.0 Hz, and its emf

lana [24]

Answer:

38 m

Explanation:

Number of turns=N=100

Magnetic field=B=0.50 T

Frequency of the generator=f=60 Hz

Rms value of emf= $E_{rms}=120 V$

We have to find the length of the wire from which the coil is made.

Peak value of emf= $E_0=E_{rms}\sqrt 2=120\times \sqrt 2=169.7 V$

Length of wire= $4\sqrt{\frac{NE_0}{2\pi fB}}$

Substitute the values

Length of wire= $4\times \sqrt{\frac{169.7\times 100}{0.50\times 2\pi\times 60}}$

Length of wire=38 m

Hence, the length of wire from which the coil is made=38 m

6 0

3 years ago

Robin Hood wishes to split an arrow already in the bull's-eye of a target 40 m away.

tamaranim1 [39]

Answer:

5.843 m

Explanation:

suppose that the arrow leave the bow with a horizontal speed , towards he bull's eye.

lets consider that horizontal motion

distance = speed * time

time = 40/ 37 = 1.081 s

arrow doesnot have a initial vertical velocity component. but it has a vertical motion due to gravity , which may cause a miss of the target.

applying motion equation

(assume g = 10 m/s²)

$s=ut+\frac{1}{2}*gt^{2} \\= 0+\frac{1}{2}*10*1.081^{2}\\= 5.843 m$

Arrow misses the target by 5.843m ig the arrow us split horizontally

4 0

3 years ago

While standing on a balcony a child drops a penny. The penny lands on the ground floor 1.5 s later. How fast was the penny trave

sveticcg [70]

Answer:

14.7 m/s.

Explanation:

From the question given above, the following data were obtained:

Time (t) = 1.5 s

Acceleration due to gravity (g) = 9.8 m/s².

Height = 11.025 m

Final velocity (v) = 0 m/s

Initial velocity (u) =?

We, can obtain the initial velocity of the penny as follow:

H = ½(v + u) t

11.025 = ½ (0 + u) × 1.5

11.025 = ½ × u × 1.5

11.025 = u × 0.75

Divide both side by 0.75

u = 11.025/0.75

u = 14.7 m/s

Therefore, the penny was travelling at 14.7 m/s before hitting the ground.

8 0

3 years ago

Who ever answers Frist get marked the Brainly Est

natka813 [3]

Answer:

Explanation:

It would actually be A. 30 , as each hour of ascension (i am not sure about the correct terminology) equals 15 .

3 0

2 years ago

Read 2 more answers