Answer:
bromine
Explanation:
Any element in the halogen group will have seven valence electrons. These elements include fluorine, chlorine, bromine, iodine, and astatine
- Mass of the car (m) = 2000 Kg
- Initial velocity (u) = 15 m/s
- Force (F) = 10000 N
- Time (t) = 3 s
- Let the acceleration be a.
- By using the formula, F = ma, we get,
- 10000 N = 2000 Kg × a
- or, a = 10000 N ÷ 2000 Kg
- or, a = 5 m/s^2
- Let the final velocity be v.
- By using the formula, v = u + at, we get,
- v = 15 m/s + 5 m/s^2 × 3 s
- or, v = 15 m/s + 15 m/s
- or, v = 30 m/s
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Doubt clarification - use comment section.
The answer is E. Short and thick while cold.
Answer:
Explanation:
Due to heat energy , metal expands . Formula for linear expansion is as follows .
L = l ( 1 + α Δt )
where L is expanded length , l is original length , α is coefficient of linear expansion and Δt is increase in temperature .
To pass the sphere through the ring , the diameter of both ring and sphere should be same after heating . Let after increase of temperature Δt , their diameter becomes same as L . The linear coefficient of brass and steel are
20 x 10⁻⁶ and 12 x 10⁻⁶ respectively .
For steel sphere ,
L = 25 ( 1 + 12 x 10⁻⁶ Δt )
For brass ring
L = 24.9 ( 1 + 20 x 10⁻⁶ Δt )
25 ( 1 + 12 x 10⁻⁶ Δt ) = 24.9 ( 1 + 20 x 10⁻⁶ Δt )
1.004( 1 + 12 x 10⁻⁶ Δt ) = ( 1 + 20 x 10⁻⁶ Δt )
1.004 + 12.0482 x 10⁻⁶ Δt = 1 + 20 x 10⁻⁶ Δt
.004 = 7.9518 x 10⁻⁶ Δt
Δt = 4000 / 7.9518
= 503⁰C.
final temp = 503 + 15 = 518⁰C .
