
- The angle between the two vectors is 90° .

- The dot product of two vectors .
- The cross product of two vectors .

⚡ Let
and
are the two vectors .
✍️ We have know that,

Where,



[1] The dot product of two vectors is “ <u>0</u> ” .
✍️ We have know that,

Where,



[2] The cross product of two vectors is “ <u>ab</u> ” .
Answer:
660 J/kg/°C
Explanation:
Heat lost by metal = heat gained by water
-m₁C₁ΔT₁ = m₂C₂ΔT₂
-(0.45 kg) C₁ (21°C − 80°C) = (0.70 kg) (4200 J/kg/°C) (21°C − 15°C)
C₁ = 660 J/kg/°C
Answer:
- <u>2.79 N</u>
- <u>8.34 N</u>
- <u>Watermelon</u>
Explanation:
<u>Weight of soccer ball</u>
- Weight = mass (in kg) × gravitational force
- Weight = 284 x 10⁻³ x 9.81
- Weight = 0.284 x 9.81
- Weight = <u>2.79 N</u> (approximately)
<u>Weight of watermelon</u>
- Weight = mass (in kg) x gravitational force
- Weight = 850 x 10⁻³ x 9.81
- Weight = 0.85 x 9.81
- Weight = <u>8.34 N</u> (approximately)
As the <u>watermelon</u> has more weight, it will hit the ground first.
If only internal forces are doing work (no work done by external forces), then there is no change in the total amount of mechanical energy. The total mechanical energy is said to be conserved. ... In these situations, the sum of the kinetic and potential energy is everywhere the same.
Solar energy ....................