My answer i believe is simply 250 Hz, because sounds or vibrations travel in 1 cycle/second, meaning the number of cycles, in your case 250, divided by the time,1 second, will ultimately be 250 Hertz. For every Cycle/second it will equal 1 Hz, so 250/1 = 250Hz
26.2005 m/s will be the velocity of the apple right when it hits the ground and the initial velocity would be 25.8235 m/s
so Vf=26.2005
and Vi=25.8235
the velocity difference is due to the apple having an initial height of 1 meter
Answer:
The magnetic flux density is 3 x 10⁵ Wb/m²
Explanation:
Given;
magnetic flux of each line of force, Ф = 30 Wb
area of the bar magnet, A = 1 cm² = 1 x 10⁻⁴ m²
The flux density of the magnet is the measure of the concentration of the magnetic flux per unit area. The unit is Wb/m² or Tesla.
B = Ф / A
B = 30 / (1 x 10⁻⁴ )
B = 3 x 10⁵ Wb/m²
Therefore, the magnetic flux density is 3 x 10⁵ Wb/m²
Assuming that there is no heat loss, and the cup is perfectly insulated, all of the energy lost by the lead will be absorbed by the water.
The heat absorbed is given by:
Energy = mass * specific heat capacity * change in temperature
The specific heat capacity of water is 4.18 joules per gram.
In order to compute the mass, we will use the fact that the density of water is one gram per milliliter. Therefore, the mass of water is 50 grams.
Now,
Q = 50 * 4.18 * (20 - 18)
Q = 418 J
418 Joules of energy were released by the lead.
-- While gaining 2.15 m/s more speed every second, the van
would gain (2.15 x 7) = 15.05 m/s more speed in 7 seconds.
-- We're told that its speed at the end of the 7 seconds
is 20 m/s .
-- So its speed at the beginning of the 7 seconds must have been
(20 m/s - 15.05 m/s) = 4.95 m/s .
