The answer is C, as there is not increase or decrease in speed during that time frame.
Answer:
8000J
Explanation:
The kinetic energy of the car lost during breaking are converted to thermal energy and are gained by the brakes.
Kinetic energy loss by car = thermal energy gained by brakes.
∆K.E = ∆T.E ....1
The Kinetic energy loss by car can be expressed as;
∆K.E = K.E1 - K.E2
Initial K.E = K.E1 = 10000J
Final K.E = K.E2 = 2000J
∆K.E= 10000J - 2000J = 8000J
From equation 1,
∆K.E = ∆T.E
∆T.E = 8,000J
thermal energy gain by brakes = 8,000J
Answer:
Explanation:
For resistance of a wire , the formula is as follows
R = ρ L / S
where ρ is specific resistance , L is length and S is cross sectional area
Given L = 14 000 m ,
S = 4.8 x 10⁻⁴ m²
specific resistance of aluminum = 2.8 x 10⁻⁸ ohm-meter
Putting the values in the formula
R = 2.8 x 10⁻⁸ x 14 x 10³ / (4.8 x 10⁻⁴ )
R = 0.8167 ohm .
= .82 ohm .
Answer:
<em><u>It can be a solid, liquid, gas</u></em><em><u>,</u></em><em><u>plasma</u></em><em><u>,</u></em><em><u>etc</u></em><em><u>. When waves travel through a medium, the particles of the medium are not carried along with </u></em><em><u>the</u></em><em><u> </u></em><em><u>wave</u></em><em><u>.</u></em><em><u>For example, water waves have to travel in water. Sound waves need a solid, a liquid or a gas to travel in.</u></em>
I think that from the answers above the answer is B.
