Answer:
A
Explanation:
Given that two balls are in motion. A 2-kg ball moving at 4m/s and a 4-kg ball moving at 2m/s, which one has greater kinetic energy? a. 2 kg ball moving at 4 m/s c. Both balls have the same KE b. 4 kg ball moving at 2 m/s d. Cannot be determined
The formula for kinetic energy is :
K.E = 1/2mv^2
A 2-kg ball moving at 4m/s will have kinetic energy of 1/2 × 2 × 4^2
K.E = 16J
and a 4-kg ball moving at 2m/s will have kinetic energy of 1/2 × 4 × 2^2
K.E = 2 × 4
K.E = 8J
which one has greater kinetic energy? Definitely it is a 2 kg ball moving at 4 m/s. Since 16J is greater than 8J. The correct answer is A.
That's false.
The definition of momentum is (mass) x (speed), so they must be multiplied.
"20,000 kg-m/s" has the correct units resulting from multiplication, but the number could only be the result of division.
Answer:
The question is not improper, But I will try to explain your doubt.
- The pot and part of stove are obviously in contact with each other. It is known <em>as conduction</em>
- The pot on gas stove burner, the air above the stove is heated and because it is gas moves upwards, this is <em>convection</em>. The bottom of the pot and surface of the stove are not 100% flat. Thats why there will be little pockets of air underneath the pot,even if you place it on the stove.
If we heat up the stove as much as then it turns to red, this visible sign is known as<em> radiation.</em>
<em>Therefore all the 3 kinds of heat transfer takes place</em>
