Answer:
To balance an equation such as Mg + O2 → MgO, the number of the atoms in the product must equal the number of the atoms in the reactant. Mg + O2 --> MgO. To balance an equation, we CAN change coefficients, but NOT SUBSCRIPTS to balance equations.
Explanation:
Answer:

Explanation:
Let assume that ball strikes a vertical wall in horizontal direction. The situation can be modelled by the appropriate use of the definition of Moment and Impulse Theorem, that is:


The average force acting on the ball during the collision is:


<h2>
Weight of astronaut 2450 miles above the Earth is 80.38 pounds</h2>
Explanation:
Given that gravitational force, F, between an object and the Earth is inversely proportional to the square of the distance from the object and the center of the Earth.

Where F is gravitational force between an object and the Earth, r is the distance from the object and the center of the Earth and k is a constant.
Radius of Earth = 4000 miles
In case 1 an astronaut weighs 209 pounds on the surface of the Earth,

Now we need to find weight of astronaut 2450 miles above the Earth
r = 4000 + 2450 = 6450 miles

Weight of astronaut 2450 miles above the Earth is 80.38 pounds
Answer:
Explanation:
Kinetic energy of block will be converted into heat energy by friction .
Heat energy produced = 1/2 m v²
= .5 x 4.8 x 1.2²
= 3.456 J
85% of energy is converted into heat energy , so heat energy produced
= .85 x 3.456 = 2.9376 J .
If Q heat is given to m mass of object having s as specific heat and Δt is increase in temperature
Q = msΔt
specific heat of iron s = 462 J / kg C
Putting the values ,
2.9376 = 4.8 x 462 x Δt
Δt = 13.24 x 10⁻⁴ ⁰C.