Answer:
174.85 W
Explanation:
Area of plate = 3.14 x (15x 10⁻²)²
= 706.5 x 10⁻⁴ m²
heat being radiated by convection = 12 x 706.5 x 10⁻⁴ ( 180 - 15 )
= 139.88 W. This energy needs to be fed by heat source to maintain a constant temperature of 180 degree.
If power of electric source is P
P x .8 = 139.88
P = 139.88 / .8
= 174.85 W
Answer:
Newton's first law of motion states that an object at rest will remain at rest and an object in motion will remain in motion unless it is acted on by an unbalanced force. Using unbalanced forces to control the motion of a skateboard demonstrates Newton's first law of motion.
Hope it helps
Gravitational force on a satellite is given by the formula

now here we know that force on the satellite is F when its distance from center of Earth is R
Now the distance from the center of earth will be 3R so the force is given as


so if we compare it with initial value of force then it is

so correct answer is

D. lost an electron
because they have free electron in the outermost shell which they will like to denote, in order to attain stable configuration