Helllllllppppp

which phenomenon is most directly responsible for earth’s magnetic field? Earth spinning on its axis. The moon's gravitational p

Scorpion4ik [409]

Earth spinning on its axis

5 0

4 years ago

A boy reaches out of a window and tosses a ball straight up with a speed of 10 m/s. The ball is 20 m above the ground as he rele

HACTEHA [7]

Answer:

25 m

9.9 m/s

22 m/s

Explanation:

m = Mass of ball

v = Velocity

g = Acceleration due to gravity = 9.81 m/s²

Applying conservation of energy

$mgh=\dfrac{1}{2}mv^2\\\Rightarrow h=\dfrac{v^2}{g}\\\Rightarrow h=\dfrac{10^2}{2\times 9.81}\\\Rightarrow h=5.09683\ m$

The height above the ground is 5.09683+20 = 25.09683 m = 25 m

$mgh=\dfrac{1}{2}mv^2\\\Rightarrow v=\sqrt{2gh}\\\Rightarrow v=\sqrt{2\times 9.81\times 5}\\\Rightarrow v=9.9\ m/s$

The ball's speed as it passes the window on its way down is 9.9 m/s

$mgh=\dfrac{1}{2}mv^2\\\Rightarrow v=\sqrt{2gh}\\\Rightarrow v=\sqrt{2\times 9.81\times 25}\\\Rightarrow v=22.14723\ m/s$

The speed of impact on the ground is 22 m/s

7 0

3 years ago

on a Powerline birds can enjoy sitting from one live wire to the other. However,if a person touches it,then the person will die

Alika [10]

Answer:

Due to potential difference (elaborated in explanation)

Explanation:

When a bird sits on a power line, its whole body is in contact with the power line. It does not have any contact with the ground or anything at a lower potential. Hence, the current does not flow through the bird's body, because there is no potential difference available as a driving force.

Now, when a person touches the power line his hand is at a higher potential provided by the power line, while the rest of his body is connected to the ground, usually through legs. The current always looks for a path from high potential to low potential. Therefore, the body of the person serves as the path for the current. Heavy current flows through the body and the person dies within split seconds.

7 0

3 years ago

How many significant figures does the number 0.0030 have? A) 1 B) 2 C) 4 D) 3

aniked [119]

My Answer: b)2

Scientific Notation: 3.0 × 10^-3

8 0

3 years ago

Read 2 more answers

Car A m= 2000kg v=20 km/h Car B m= 2000kg v= 20km/h what is the location after impact

Darya [45]

Mass of car, M=2000kg

Velocity, V=72× 5/18 =20ms¹

Apply kinematic equation of motion

v² -u² = as

0 − 20² =2a×20

a=−10ms^-2

Breaking force, F=ma=2000×10=20 kN

Apply first kinematic equation

v = u +at

$t= \frac{v - u}{a} = \frac{0 - 20}{ - 10} = 2sec\\$

7 0

3 years ago