Answer:
96%
Explanation:
To find the values of the motor efficiency you use the following formula:

P_o: output power = 864J/0.5min=864J/30s=28.8W
P_i: input power = I*V = (3A)(12V) = 36W
By replacing this values you obtain:

hence, the motor efficiency is about 96%
traslation:
Pentru a găsi valorile eficienței motorului, utilizați următoarea formulă:
P_o: putere de ieșire = 864J / 0.5min = 864J / 30s = 28.8W
P_i: putere de intrare = I * V = (3A) (12V) = 36W
Înlocuind aceste valori obțineți:
prin urmare, eficiența motorului este de aproximativ 96%
<span>B. If the temperature of a solid is increased, the solid expands and its volume increases.</span>
Answer:
A box sits stationary on a ramp
Explanation:
Static friction is a force which keeps an object at rest as it is in the case of the box. It has to be overcome for the object to be set into motion.
Static force of friction is calculated as follows:
F= μη
F is static force of friction.
μ is the coefficient of static friction.
η is the normal force.
Answer:
not clear pic...but it's definitely not A)
Answer:
I think it's bigger than most galaxies