Answer:
22.2 W
Explanation:
First of all, we calculate the work done by moving the wagon, using the formula:
where
F = 20 N is the magnitude of the force
d = 1000 m is the displacement of the wagon
is the angle between the direction of the force and of the displacement (assuming the force is applied in the direction of motion)
Substituting, we find
Now we can find the power generated, which is equal to the ratio between the work done and the time taken:
where
W = 20,000 J
t = 15 min = 900 s
Substituting,
And the same value in Joules/second (remember that 1 Watt = 1 Joule/second)
TRUE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Answer:
0.66c
Explanation:
Use length contraction equation:
L = L₀ √(1 − (v²/c²))
where L is the contracted length,
L₀ is the length at 0 velocity,
v is the velocity,
and c is the speed of light.
900 = 1200 √(1 − (v²/c²))
3/4 = √(1 − (v²/c²))
9/16 = 1 − (v²/c²)
v²/c² = 7/16
v = ¼√7 c
v ≈ 0.66 c
I think it's a) 1st Newton's law... so sorry if it's wrong...
