Answer:
In the first law, an object will not change its motion unless a force acts on it. In the second law, the force on an object is equal to its mass times its acceleration. In the third law, when two objects interact, they apply forces to each other of equal magnitude and opposite direction
Explanation:
Answer:
18%
Explanation:
There are two equal and opposite forces on a floating object: weight and buoyancy.
W = B
The weight of an object is its mass times gravity: W = mg
Buoyancy is the weight of the displaced fluid: W = mf g
Plugging in:
mg = mf g
m = mf
Mass is density times volume:
ρV = ρf Vf
Solving for the ratio of Vf / V:
Vf / V = ρ / ρf
Given that ρ = 0.82 g/mL and ρf = 1.00 g/mL:
Vf / V = 0.82
That means 82% of the object's volume (and therefore, 82% of its mass, assuming uniform density) is submerged. Which means that 18% is above the water line.
Answer:
Explanation:
Since the compass uses a magnetic field, if anything else magnetic is near it, the compass will start acting up. Making it unreliable so keep magnets away!
Answer:
The velocity of the penny at 25th second is, v = 245 m/s
Explanation:
Given,
The time taken by the penny to hit the ground is, t = 30 s
The initial velocity of the penny, u = 0 m/s
The velocity of the penny at 25th second, v = ?
Using the II equation of motion, the displacement is given by the formula
<em> S = ut + ½ gt²</em>
= 0 + ½ x 9.8 ( 25²)
= 3062.5 m
Using the III equations of motion
<em>v² = u² + 2gs</em>
Substituting the given values,
v² = 0 + 2 x 9.8 x 3062.5
= 60025
v = 245 m/s
Hence, the velocity of the penny at 25th second is, v = 245 m/s
