Answer:
1065 Kgm-3
Explanation:
We can determine the relative density of the athlete from the formula;
Relative density of athlete = weight of athlete in air/upthrust on athlete
Since weight of athlete in air= 690 N
Weight of athlete in water = 42 N
Upthrust on athlete= weight in air - weight in water
Upthrust on athlete= 690 N - 42 N = 648 N
Relative density of athlete= 690 N / 648 N
Relative density of athlete= 1.065
Therefore, average density of the athlete= relative density × density of water = 1.065 × 1000 Kgm-3 = 1065 Kgm-3
Newton's second law - the law of acceleration (acceleration = force/mass). Newton's second law states that the acceleration of an object is directly related to the net force and inversely related to its mass. Acceleration of an object depends on two things, force and mass.
Answer:
If you know the total current and the voltage across the whole circuit, you can find the total resistance using Ohm's Law: R = V / I. For example, a parallel circuit has a voltage of 9 volts and total current of 3 amps. The total resistance RT = 9 volts / 3 amps = 3 Ω.
Explanation:
The block has maximum kinetic energy at the bottom of the curved incline. Since its radius is 3.0 m, this is also the block's starting height. Find the block's potential energy <em>PE</em> :
<em>PE</em> = <em>m g h</em>
<em>PE</em> = (2.0 kg) (9.8 m/s²) (3.0 m)
<em>PE</em> = 58.8 J
Energy is conserved throughout the block's descent, so that <em>PE</em> at the top of the curve is equal to kinetic energy <em>KE</em> at the bottom. Solve for the velocity <em>v</em> :
<em>PE</em> = <em>KE</em>
58.8 J = 1/2 <em>m v</em> ²
117.6 J = (2.0 kg) <em>v</em> ²
<em>v</em> = √((117.6 J) / (2.0 kg))
<em>v</em> ≈ 7.668 m/s ≈ 7.7 m/s