Answer:
Explanation:
18 km / h
= 300 m / min
12 km / h = 200 m / min
distance travelled in 200 minutes = 300 x 200 = 60000 m
distance travelled in 50 minute in return journey = 200 x 50 = 10000 m
total distance travelled = 70000 m
total time = 250 minute
speed = 70000 / 250
= 280 m / min
= 16.8 km / h
Total displacement = 60000 - 10000 = 50000 m
total time = 250 min
velocity = 50000 / 250
= 200 m / min
= 12 km / h
Answer:
1.28second
Explanation:
The speed of light is constant everywhere, it is
299,792,458m/s=299,792.458km/s
Therefore it takes
Answer:
The elevator must be moving upward.
Explanation:
During the motion of an elevator, the weight of the person deviates from his or her actual weight. This temporary weight during the motion is referred to as "Apparent Weight". So, when the elevator is moving downward, the apparent weight of the person becomes less than his or her actual weight.
On the other hand, for the upward motion of the elevator, the apparent weight of the person becomes more than the actual weight of that person.
Since the apparent weight (645 N) of the student, in this case, is greater than the actual weight (615 N) of the student.
<u>Therefore, the elevator must be moving upward.</u>
Answer:
a) f₁ = 3.50 m
, b) f₂ = 0.84 m
Explanation:
For this exercise we must use the constructor equation
1 / f = 1 / p + 1 / q
where f is the focal length, p is the distance to the object and q is the distance to the image
a) the distance where the image should be placed is q = 3.50 m and the object is located at infinity p = ∞
1 / f₁ = 1 /∞ + 1 / 3.50
f₁ = 3.50 m
b) in this case the image is at q = -0.600 m and the object p = 0.350 m
1 / f₂ = 1 / 0.350 -1 / 0.600
the negative sign, is because the image is in front of the object
1 / f₂ = 1,1905
f₂ = 1 / 1,1905
f₂ = 0.84 m
The SI unit for molar mass is grams/mole.
