Answer:
Questions that cannot be answered through scientific investigation are those that relate to personal preference, moral values, the supernatural, or unmeasurable phenomena.
Answer:
Explanation:
let force exerted by engine be F.Net force =( F-400)N, applying newton law
F-400 = 1.5 x 10³x18 =27000 ,
F = 27400 N.
velocity after 12 s = 0 + 18 x 12 = 216 m/s
Average velocity = (0 + 216 )/2 = 108 m/s
Average power = force x average velocity = 27400 x 108 = 29.6 10⁵ W .⁶
b) At 12 s , velocity = 216 m/s
Instantaneous power = velocity x force = 216 x 27400 = 59.2 x 10⁶ W.
Answer:
Wg is positive and WT negative.
(Letters in options are all wrongly written).
Explanation:
Remember that the work of a force is the internal product between the force and the displacement
.
Since the displacement is downwards like the weight, the work done by gravity is positive, while the work done by the tension is negative since it points upwards.
Answer:
a = - 11.53[m/s^2]
Explanation:
The airplane slows down as its speed decreases from the initial value of 610 [m/s] to zero.
To calculate the acceleration value we use the following kinematics equation:
![v_{f} = v_{i}+(a*t)\\](https://tex.z-dn.net/?f=v_%7Bf%7D%20%3D%20v_%7Bi%7D%2B%28a%2At%29%5C%5C)
where:
Vf = final velocity = 0
Vi = initial velocity = 610 [m/s]
a = acceleration [m/s2]
t = time = 53 [s]
Now replacing:
0 = 610 + (a*53)
-610 = 53*a
a = - 11.53[m/s^2]
The negative sign means that the aircraft is losing speed, i.e. slowing down
Construct an hypothesis <em /><em>(Because </em>the magnet wasn't attracted to the door, the door must be non-magnetic.) He has already made an observation (the magnent didn't stick), and already asked a question (<em>Why </em>didn't the magnent stick). However, he has not explained the results (there is no experiment yet).