Answer:
1.4E-3J
Explanation:
Given that
Time = 8hrs = 28.8E3 seconds
Intensity= 90dB
D= 0.008m
Radius= 0.004m
So intensity is sound level Bis
10dBlog(I/Io)
I= 10 (B/10dB)Io
= 10( 90/10) x 10^-12
=0.001W/m²
But we know that
I = P/A
P= I πr²
= 5.02 x10^-8W
But energy is power x time
So E= 5.02E-8 x 28.8E3
= 1.4E-3J
Explanation:
If we assume negligible air resistance and heat loss, we can assume that all of the Gravitational potential energy of the ball will turn into Kinetic energy as it falls toward the ground.
Therefore our Kinetic energy = mgh = (10kg)(9.81N/kg)(100m) = 9,810J.
Answer: 5.72 x 10-3Ω
Explanation:
Hi, to answer this question, first we have to calculate the cross sectional area of the cable:
Diameter (D)=6.07 mm
Since: 1000mm = 1m
6.07mm/ 1000mm/m = 0.00607 meters
Area of a circle : π (d/2)^2
A = π (0.00607/2)^2= 0.000028937 m2
Resistance formula:
Resistance (R) = P(resistivity) L (length)÷A (cross sectional area )
Replacing with the values given:
R = (2.82x10-8 x 5.87) / 0.000028937
R = 5.72 x 10-3Ω
Feel free to ask for more if needed or if you did not understand something.
Answer:
Explanation:
Convert the mass to kg:
375g = 375/1000kg = 0.375kg
F = ma
-20 = 0.375a
a = -20/0.375
a = -53
The object is accelerating at 53m/s/s backwards assuming that the forward motion is positive.
