Answer: D
8.403 m/s
Explanation:
Given that the women's world record for the 400-meter run around an oval track is held by Marita Koch, with a time of 47.60
seconds.
Her average velocity during this race will be
Velocity = distance/ time
Velocity = 400 / 47.6
Velocity = 8.403 m/s
Therefore, her average velocity during this race will be 8.403 m/s
D is therefore the correct answer.
Answer:
1. A
2. B or C
Explanation:
1.
F=ma, meaning that if you use two times more force on a constant mass, the acceleration must double. Acceleration is change in velocity, which means that if you are aiming for the same final velocity the change must happen in half of the time. Therefore, the correct answer is choice A.
2.
By Newton's first law, an object in motion will stay in motion unless an external force acts on it. Since there is nothing pushing the puck in the other direction, the puck will either keep on going for at a constant velocity or will reduce its speed gradually, depending on whether or not this ice is considered to be frictionless. Hope this helps!
Answer:
FALSE
Explanation:
When object float in water then it means that weight of the object is counterbalanced by the buoyancy force.
Here as we know that buoyancy force is the weight of water displaced by the object.
So here when object is submerged into the water then the submerged part of the volume of object will displace exactly the same volume of water and that volume of water will exert upwards buoyancy force on the object.
So here this statement is not true as it says that volume of water displaced is volume above the surface of water while it must be like volume of water displaced must be equal to volume of submerged part of the object.
Answer: B superconductors
Explanation:
Answer:
field B = µ₀c I / 2πr
The field in the xy plane due to the fact that the two wires are perpendicular to the plane Bx and By are everywhere 0 on the plane.
a) Midway between, the Bz components cancel, so <0, 0, 0> T
b) Bz = µ₀ x I / 2πa + µ₀ x I / 2π(3a) = (µ₀ x I / 2π)(1/a + 1/3a)
Bz = (µ₀ x I / 2πr)(3/3a + 1/3a) = (µ₀x I / 2πr)(4 / 3a) = 2µ₀ x I / 3πa
c) By symmetry, Bz = -2µ₀ x I / 3πa (that is, down into the plane)
