A man runs 300 m West in 60 seconds. He then runs 100 m
North-west in 20 seconds.
What is his average velocity in metres per second?​

Answer:

D. The air we breathe is a homogeneous mixture because it has substances but the same appearance throughout.

Explanation:

The air we breathe is a homogeneous mixture.

Air is a mixture of many gases. A homogeneous mixture is one whose constituents exists in one phase.

Air is a gas - gas mixtures.

A mixture has indefinite composition. They consist of two or more elements and or compounds in any proportion by mass.

Constituents retain their identities i.e. physical properties are retained.

Answer:

G. 6125

Explanation:

Step one:

given data

mass m=  2.5x10-3 kg

velocity v= 7000 m/s

Required

The kinetic energy

Step two:

The expression for the kinetic energy is

KE= 1/2m v^2

KE= 1/2*2.5x10^-3*7000^2

KE= 0.5*2.5x10^-3*7000^2

KE= 0.5*2.5x10^-3*49000000

KE= 0.5*122500

KE=6125J

Answer:

High temperature of 108 million K

Explanation:

For the fusion reactor to be able to work optimally, then one of the most important conditions is the necessity of a very high temperature of about 108 million Kelvin. This is quite large, and is about six times hotter than the temperature existing at the core of the sun. At this temperature, the hydrogen state of the element is not a gas, but rather it is a plasma. Here, the atoms will be stripped of their electrons and are allowed to move freely. This condition is akin to the perfect condition for the reactor to function. It makes the hydrogen atoms gather enough energy for the reaction that takes place in the subsequent phases of this process.

Answer:

the net force on the car is 8,000 N.

Explanation:

Given;

mass of the car, m = 800 kg

motive force of the car, F = 10,000 N

frictional force experienced by the car, Fk = 2,000 N

The net force on the car is calculated as;

∑F = F - Fk

∑F = 10,000 - 2,000

∑F = 8,000 N

Therefore, the net force on the car is 8,000 N.

Answer:

find it yourself too lazy for math but here's the step

Explanation:

it's the object mass multiplied by the velocity.

Given :

A tourist drops (from rest) a ping pong ball from the top of the tower, which has a height of 174 meters.

To Find :

How long does it take for the ping pong ball to hit the ground ?

Solution :

We know, equation of motion of object doing free fall is :

[tex]s = ut + \dfrac{gt^2}{2}[/tex]           ....1)

Here, g = 9.8 m/s² ( acceleration due to gravity )

Also, u = 0 m/s ( its free fall )

Putting these values in equation 1), we get :

[tex]174 = 0 + \dfrac{9.8\times t^2}{2}\\\\t = \sqrt{\dfrac{174\times 2}{9.8} }\ s\\\\t = 5.96 \ s[/tex]

Therefore, ball will take 5.96 s to hit the ground.