Answer:
64 J
Explanation:
The potential energy change of the spring ∆U = -W where W = work done by force, F.
Now W = ∫F.dx
So, ∆U = - ∫F.dx = - ∫Fdxcos180 (since the spring force and extension are in opposite directions)
∆U = - ∫-Fdx
= ∫F.dx
Since F = 40x - 6x² and x moves from x = 0 to x = 2 m, we integrate thus, ∆U = ∫₀²F.dx
= ∫₀²(40x - 6x²).dx
= ∫₀²(40xdx - 6x²dx)
= ∫₀²(40x²/2 - 6x³/3)
= ∫₀²(20x² - 2x³)
= [20x² - 2x³]₀²
= [(20(2)² - 2(2)³) - (20(0)² - 2(0)³)
= [(20(4) - 2(8)) - (0 - 0))
= [80 - 16 - 0]
= 64 J
Should be an air tight seal
Answer:
Speed = 0.00392 m/s
Explanation:
Solution:
Frequency of the radio = 85 MHz
If we have the frequency, we can calculate the wavelength of the radio wave.
As we know,
Frequency = speed of light/wavelength
wavelength = c/f
c = speed of light = 3 x 
m/s
So,
Wavelength = 3 x m/s / 85 x 
Hz
Wavelength = 3.5294 m
Man gets disturbed reception at t = 15 min
t = 15 x 60 = 900 s
t = 900 s
Speed = distance/time
Here, distance is wavelength. So,
Speed = 3.5294 m / 900 s
Speed = 0.00392 m/s
Hence, the man's car is going with speed of 0.00392 m/s
Answer:
The answer to your question will be d) greater the pressure
Explanation:
given:
mass = 5000 kg
u (initial velocity) = 0 m/s
v (final velocity) = 70 m/s
time taken to change velocity = 3600 s
acceleration = v - u / t
a = 70 - 0 / 3600
a = 70 / 3600
a = 0.0194 m/s2 (approx)
given: mass = 5000 kg
acceleration = 0.0194 (found in 1st part)
force = mass * acceleration
f = ma
f = 5000*0.0194 = 97 N
therefore the acceleration will be 0.0194 m/s2
and the force involved in acceleration will be 97 N
