Answer:
The work done by the wind as the boat moves 130 ft is (rounded) W= 31,550 ft-lb.
Explanation:
F= 300 lb < -54º
Fsouth= 300 lb * cos(36º)
Fsouth= 242.7 lb
d= 130 ft
W= F*d
W= 31551 ft-lb
Time taken to complete one oscillation for a pendulum is Time Period, T = 0.5 s
Frequency of the pendulum oscillation = 1 / Time Period => f = 1 / T = 1 / 0.5
Frequency f = 2 Hz
Answer:
The difference in the length of the bridge is 0.42 m.
Explanation:
Given that,
Length = 1000 m
Winter temperature = 0°C
Summer temperature = 40°C
Coefficient of thermal expansion 
We need to calculate the difference in the length of the bridge
Using formula of the difference in the length

Where,
= temperature difference
=Coefficient of thermal expansion
L= length
Put the value into the formula


Hence, The difference in the length of the bridge is 0.42 m.
Answer:
wavelength = 24 m
Period = 10 s
f = 0.1 Hz
Amplitude = 4 m
Explanation:
Wavelength:
Since the boats are at crest and trough, respectively at the same time. Hence, the horizontal distance between them is the wavelength of the wave:
<u>wavelength = 24 m</u>
Period:
The period is given as:

<u>Period = 10 s</u>
<u></u>
Frequency:
The frequency is given as:

<u>f = 0.1 Hz</u>
<u></u>
Amplitude:
Amplitude will be half the distance between extreme points, that is, crest and trough:
Amplitude = 8 m/2
<u>Amplitude = 4 m</u>
The electrostatic force between two charges q1 and q2 is given by

where

is the Coulomb's constant and r is the distance between the two charges.
If we use F=19.2 N and q1=q2=-3.0 C, we can find the value of r, the distance between the two charges by re-arranging the previous formula: