Power = (work or energy) / (time)
100 W = (energy) / (20 sec)
Energy = 2,000 watt-sec
<em>Energy = 2,000 J</em>
Answer:
C. Quadruple the intensity
Explanation:
The intensity of the sound is proportional to square of amplitude of the sound.
I ∝ A²
When the given sound is twice loud as the initial value, then the new amplitude is twice the former.
A₂ = 2A₁
Thus, to make a given sound seem twice as loud, the musician should Quadruple the intensity
Answer:
lower
Explanation:
The lower the value of the coefficient of friction, the lower the resistance to sliding.
The coefficient of friction is the ratio of the frictional force and the normal force pressing two surfaces in contact together.
U =
U is the coefficient of friction
F is the frictional force
N is the normal force
We see that coefficient of friction is directly proportional to frictional force.
Answer:
Speed of cart's might be less than the high speed after 5 seconds.
Explanation:
Given that,
A fan cart with the fan set to high rolled across the floor.
Let the speed of fan cart with set to high is per second.
The fan supplies a force to the cart. If a lower fan speed were used, less force would be applied. This would cause a slower change in the cart's speed. So, the cart would be rolling more slowly than per second after 5 seconds. The speed of cart's might be less than per second.
Force is needed
A. for a moving object to keep moving at the same speed and direction
B. for a moving object to change its speed
C. for a motionless object to remain still
D. to prevent a moving object from turning
Hence,
Speed of cart's might be less than the high speed after 5 seconds.
Well, if I understand correctly, I think it'd be 60, because 60+60= 120, but I may be wrong. It's not my best subject, but why not try to help even though I suck lol.