In the figure below, the scale on which the 63 kg physicist stands reads 236 N. How long will the cantaloupe take to reach the floor if the physicist drops it (from rest relative to himself) at a height of 2.1 m above the floor?
How would you go about solving this?
I = P/A = P/4πr² = 100/4π(8)² = 0.12 W•m⁻²
If the sound intensity level is halved to a value of I = 0.06 W•m⁻²,
the sound intensity level will decrease by 3 dB.
I = P/4πr² = 100/4π(x) ² =
=0.06 W•m⁻²
x = 11.5 m from the speaker.
It says that the answer isn't right. I already tried using the same method. Thanks though!
To solve this problem, we need to apply the principle of conservation of energy. The potential energy of the cantaloupe at the initial height is converted into kinetic energy as it falls. We can equate the initial potential energy to the final kinetic energy to solve for the time it takes for the cantaloupe to reach the floor.
Here are the steps to solve the problem:
1. Determine the potential energy of the cantaloupe at the initial height:
- Potential energy (PE) = mass (m) x gravity (g) x height (h)
- Convert the mass of the cantaloupe from kg to N by multiplying by the acceleration due to gravity (g ≈ 9.8 m/s^2).
2. Calculate the final kinetic energy of the cantaloupe just before it hits the ground:
- Kinetic energy (KE) = 0.5 x mass x velocity^2
- Since the cantaloupe is dropped from rest, the initial velocity is zero.
3. Equate the initial potential energy to the final kinetic energy and solve for the velocity:
- PE = KE
- Substitute the formulas for potential energy and kinetic energy into the equation and solve for velocity.
4. Use the velocity obtained to calculate the time it takes for the cantaloupe to reach the floor:
- Time (t) = distance (d) / velocity
- The distance is equal to the initial height of the cantaloupe (2.1 m).
By following these steps, you can find the answer to the question.
F=mg
g=F/m=236/63=3.746 m/s²
h=gt²/2
t=sqrt(2h/g)=sqrt(2•2.1/3.746)=1.06 s.