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3 years ago

Help please! Thanks so much!

Physics

1 answer:

qaws [65]3 years ago

4 0

You pretty much just have to convert and be mindful of significant figures.

5 km = 3 miles
0.3 cm = 0.12 in

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A 64.8 kg astronaut is on a space walk when the tether line to the shuttle breaks. The astronaut is able to throw a 11.0 kg oxyg

Umnica [9.8K]

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6 0

3 years ago

An ice sled powered by a rocket engine starts from rest on a large frozen lake and accelerates at 12.8 m/s2 . At t1 the rocket e

Simora [160]

Answer:4.39 s

Explanation:

Given

initial velocity $u=0$

acceleration $a=12.8 m/s^2$

velocity acquired by sled in $t_1$ time

$v=0+at$

$v=12.8t_1$

distance traveled by sled in $t_1 s$

$v^2-u^2=2as$

$(12.8t_1)^2-0=2\times 12.8\times s_1$

$s_1=6.4\cdot t_1^2$

distance traveled in $t_2$ time with velocity $v=12.8t_1$

$s_2=v\times t_2$

$s_2=12.8\times t_1\times t_2$

$s_2=12.8\cdot t_1\cdot t_2$

$s_1+s_2=5.37\times 10^3$

$6.4t_1^2+12.8t_1t_2=5370$ ----1

$t_1+t_2=97.7 s$

$t_2=97.7-t_1$

substitute the value of $t_2$ in 1

we get

$6.4t_1^2-1250.56t_1+5370=0$

thus $t_1=\frac{1250.56-1194.33}{12.8}=4.39 s$

$t_1=4.39 s$

5 0

3 years ago

In an effort to stay awake for an all-night study session, a student makes a cup of coffee by first placing a 200 WW electric im

ivolga24 [154]

Answer:

The heat is 115478.4 J.

Explanation:

Given that,

Mass of water = 0.400 kg

Power = 200 W

Suppose, we determine how much heat must be added to the water to raise its temperature from 20.0°C to 89.0°C?

We need to calculate the heat

Using formula of heat

$Q=mc\Delta T$

Where, m = mass of water

c = specific heat

Put the value into the formula

$Q=400\times4.184\times(89-20)$

$Q=115478.4\ J$

Hence, The heat is 115478.4 J.

7 0

3 years ago

A hypothetical planet has a mass one-third of and a radius three times that of Earth. What is the acceleration due to gravity on

kap26 [50]

Answer:

F) The acceleration due to gravity is g/27

Explanation:

According to Newton gravitational law, the gravitational acceleration is directly proportional to the planet mass and inversely proportional to the square of distance.

Since our new planet has a mass of one-third of Earth's and radius 3 times of Earth's. This means the new planet is lighter and further away from the distance. This means g is first reduced by 3 due to smaller mass and then reduced by 9 due to square of 3 times the distance.

The gravitational acceleration on this new planet must be

$\frac{g/3}{3^2}$

$\frac{g}{27}$

So F) is the correct answer

6 0

3 years ago

Can someone answer these?

Scorpion4ik [409]

Nine

Basically you are using d = r * t

Frequency is 1 / t

d is more commonly represented by lambda ( $\lambda$ ). Lambda is the wavelength.

so the formula $\lambda$ = c / f

More commonly it is written as $\lambda$ *f = c.

Givens

c = 3*10^8 m/s

$\lambda$ = 0.1 nm = 0.1 nm *[1 m /1 * 10^9 nm] = 0.1 * 10^ - 9 meters.

f = ??

f = $\dfrac{3*10^8}{0.1 * 10^-9}$

f = 3 * 10^8 * 10^9 / 0.1 = 3 * 10^18

Answer: C

Ten

$\lambda$ = c/f

$\lambda$ = 3*10^8 / 1 * 10^16

$\lambda$ = 3*10^-8 meters

$\lambda$ = 30 * 10^-9 meters = 30 nm

Answer: D

7 0

3 years ago