Answer:
1 m
Explanation:
L = 100 m
A = 1 mm^2 = 1 x 10^-6 m^2
Y = 1 x 10^11 N/m^2
F = 1000 N
Let the cable stretch be ΔL.
By the formula of Young's modulus
![Y=\frac{F\times L}{A\times\Delta L}](https://tex.z-dn.net/?f=Y%3D%5Cfrac%7BF%5Ctimes%20L%7D%7BA%5Ctimes%5CDelta%20L%7D)
![\Delta L=\frac{F\times L}{A\times\Y}](https://tex.z-dn.net/?f=%5CDelta%20L%3D%5Cfrac%7BF%5Ctimes%20L%7D%7BA%5Ctimes%5CY%7D)
![\Delta L=\frac{1000\times 100}{10^{-6}\times10^{11}}](https://tex.z-dn.net/?f=%5CDelta%20L%3D%5Cfrac%7B1000%5Ctimes%20100%7D%7B10%5E%7B-6%7D%5Ctimes10%5E%7B11%7D%7D)
ΔL = 1 m
Thus, the cable stretches by 1 m.
Answer:
85 miles .
Explanation:
Displacement along the 110 South freeway = 260 - 150 = 110 miles
Displacement along the 110 North freeway = 150 - 175 = - 25 miles
Net displacement = 110 - 25 = 85 miles
So Joey's displacement from the 260 mile marker is 85 miles .
Suppose car A is moving with a velocity Va, and car b with a velocity Vb,
According the principle of conservation of momentum:
Va x Ma + Vb x Mb = (Ma + Mb) V
V = (Va x Ma + Vb x Mb)/(Ma +Mb)
V = speed of cars after coupling
V = (Va x 20 mg + Vb x 15 mg)/(20 mg + 15 mg)
Put in the values of Va and Vb, and get the V
Acceleration occurs when velocities change.velocity changes either because the speed changes or the direction change.