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Svetllana [295]

3 years ago

5

How often do the earth's magnetic poles switch?

1 answer:

RSB [31]3 years ago

3 0

Reversals are the rule, not the exception. Earth has settled in the last 20 million years into a pattern of a pole<span> reversal about every 200,000 to 300,000 years, although it has been more than twice that </span>long<span> since the last reversal.</span>

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Physics Homework MathPhys homie if you see this pls help

cluponka [151]

Answer:

1. -8.20 m/s²

2. 73.4 m

3. 19.4 m

Explanation:

1. Apply Newton's second law to the car in the y direction.

∑F = ma

N − mg = 0

N = mg

Apply Newton's second law to the car in the x direction.

∑F = ma

-F = ma

-Nμ = ma

-mgμ = ma

a = -gμ

Given μ = 0.837:

a = -(9.8 m/s²) (0.837)

a = -8.20 m/s²

2. Given:

v₀ = 34.7 m/s

v = 0 m/s

a = -8.20 m/s²

Find: Δx

v² = v₀² + 2aΔx

(0 m/s)² = (34.7 m/s)² + 2 (-8.20 m/s²) Δx

Δx = 73.4 m

3. Since your braking distance is the same as the car in front of you, the minimum safe following distance is the distance you travel during your reaction time.

d = v₀t

d = (34.7 m/s) (0.56 s)

d = 19.4 m

6 0

3 years ago

An open system starts with 52 J of mechanical energy. The energy changes

Vikki [24]

Answer:

47 J

hope it helps u

thanks for easy ask

3 0

3 years ago

You drop a batitin a stationary elevator and the ball hits the floor in o 50 s. How long does it take for the ball to hit the fl

solmaris [256]

Answer:

option (a) 0.61 s

Explanation:

Given;

Time taken by the ball to reach the ground = 0.50 s

Let us first calculate the distance through which the ball falls on the ground

from the Newton's equation of motion, we have

$s=ut+\frac{1}{2}at^2$

where,

s is the distance

a is the acceleration

t is the time

here it is the case of free fall

thus, a = g = acceleration due to gravity

u = initial speed of the ball = 0

on substituting the values, we get

$s=0\times 0.50+\frac{1}{2}\times9.8\times0.50^2$

or

s = 1.225 m

Now,

when the elevator is moving up with speed of 1.0 m/s

the initial speed of the ball = -1.0 m/s (as the elevator is moving in upward direction)

thus , we have

$s=ut+\frac{1}{2}at^2$

or

$1.225=-1.0\times\ t+\frac{1}{2}\times9.8t^2$

or

4.9t^2 - t - 1.225 = 0

or

t = 0.612 s

hence, the correct answer is option (a) 0.61 s

4 0

4 years ago

castortr0y [4]

Answer: $Q=3000 cal$

Explanation:

We are given the following formula:

$Q=m. c. \Delta T$ (1)

Where:

$Q=3000 cal$ is the amount of heat

$m=300g$ is the mass of water

$c=1 cal/g \°C$ is the specific heat of water

$\Delta T$ is the variation in temperature, which in this case is $\Delta T=30\°C-20\°C=10\°C$

Rewriting equation (1) with the known values at the right side, we will prove the result is $3000 cal$ :

$Q=(300g)(1 cal/g \°C)(10\°C)$ (2)

$Q=3000 cal$ This is the result

8 0

3 years ago

An area where the particles in a medium are spaced close together is called a _____.

Ksju [112]

An area where the particles in a medium are spaced close together is called compression.

3 0

3 years ago

Read 2 more answers