Answer:
a) f = 453.3Hz
b) f = 443.1Hz
c) f = 420Hz
Explanation:
First of all we need to know the positions and velocities of both vehicles.
For the car:
Xc(-5) = 0m; Vc(-5) = 0m/s
; Vc(5)=2.5*5 = 12.5m/s
; Vc(10)=2.5*10=25m/s
For the truck:
Xt(-5)=10*(-5) = -50m; Vt(5)=10m/s
Xt(5)=10*5 = 50m; Vt(5)=10m/s
Xt(10)=10*10=100m; Vt(10)=10m/s
Now for part a) t=-5s. The truck is behind the car, so:

Now for part b) t=5s. The car is behind the truck, so:

Now for part b) t=10s. The truck is behind the car, so:

Answer:
See below
Explanation:
Net force acting on the plane after overcoming frictional forces is
2.7 x 10^6 - 6.8 x 10^4 - 8.5 x 10^5 = 1 782 000 N
Work = F x d
= 1 782 000 x 1400 m = 2.5 x 10^9 J or 2.5 x 10^6 kJ
Answer:
The correct answer for this Question is B
Explanation:
WIND AND WATER EROSION (B)
Light years are the distance light can travel in a full year. They are used because there are really big distances in the universe that are easier to measure with a really large form of measurement (light years).
Answer:
the length of stretched spring in cm is 22
Explanation:
given information:
spring length, x1 = 20 cm = 0.2 m
force, F = 100 N
the length of spring streches, x2 = 22 cm = 0.22 m
According to Hooke's law
F = - kΔx
k = F/*=(x2-x1)
= 100/(0.22 - 0.20)
= 5000 N/m
if the spring is now suspended from a hook and a 10.2-kg block is attached to the bottom end
m = 10.2 kg
W = m g
= 10.2 x 9.8
= 99.96 N
F = - k Δx
Δx = F / k
= 99.96 / 5000
= 0.02
Δx = x2- x1
x2 = Δx + x1
= 0.20 + 0.02
= 0.22 m
= 22 cm