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2 years ago

Define one standard meter, one standard kilogram and one second

1 answer:

6 0

<h3>The metre is the length of the path travelled by light in vacuum during a time interval of 1299 792 458 of a second.</h3>

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A flute player hears four beats per second when she compares her note to an 880 Hz tuning fork (note A). She can match the frequ

ludmilkaskok [199]

Answer:

884Hz

Explanation:

Beats is the absolute difference between two frequencies therefore

Beats = f1-f2

4=f1-880

F1=880+4

F1=884Hz

7 0

2 years ago

49 = 1/2gt²

BaLLatris [955]

Answer:

e son

Explanation:

se lo on

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2 years ago

a projectile is launched at an angle of 30 degrees and lands later at the same level. if it's initial speed is 50 m/s, solve for

Mrrafil [7]

$using \: the \: formula \\ t = \frac{2u \sin( \alpha ) }{g} where \: u = initial \: speed \: \\ \alpha = angle \: of \: projection \\ g = acceleration \: due \: to \: gravity \\ \frac{2 \times 50 \times \sin(30) }{10} \\ \frac{100 \times 0.5}{10} = \frac{50}{10} = 5seconds$

Maximum height
= (Usinα)^2/2g
(50*0.5)^2/20
25^2/20
625/20
=31.25metres
horizontal distance = Range= [U^2 * sin2α]/g
[50^2 * sin60]/10
2500 * 0.8660/10
2165/10=216.5metres

3 0

2 years ago

As part of a safety investigation, two 1900 kg cars traveling at 20 m/s are crashed into different barriers. Part A Find the ave

DedPeter [7]

Answer:

- $29.2\times 10^{3} N$

Explanation:

We are given that

Mass of cars= m=1900 kg

Initial speed of car=u=20 m/s

Final speed of car=v=0

Time= $\Delta t$ =1.3 s

We have to find the average force exerted on the car.

Average force= $\frac{change\;in\;momentum}{\Delta t}$

$F_{avg}=\frac{mv-mu}{1.3}$

$F_{avg}=\frac{1900(0)-1900(20)}{1.3}$

$F_{avg}=\frac{-38000}{1.3}=-29.2\times 10^{3} N$

Hence, the average force exerted on the car that hits a line of water barrels=- $29.2\times 10^{3} N$

8 0

3 years ago

3. An athlete makes a long jump and follows a projectile motion. Air resistance is negligible. Which one of the following statem

yulyashka [42]

Answer:

Option (b) is correct.

Explanation:

The motion under the influence of gravity is called projectile motion.

The acceleration due to gravity is constant through out the motion and it is always acting downwards.

When an athlete jumps and follow the projectile path, it always have the same horizontal velocity as there is no acceleration in the horizontal direction.

Also he has the vertical acceleration constant which is equal to the acceleration due to gravity and acts towards the center of earth.

Option (b) is correct.

6 0

2 years ago