Answer:
v = -24.5 m/s
Explanation:
Use conservation of momentum P = m*v. Unless there are external forces involved, total momentum must be conserved.
P: momentum
m: mass
v: velocity
1. calculate the total momentum before the collision:
2. the total momentum after the collision must not change:
3. after the collision the velocity of the car is the same as the velocity of the truck:
4. combining 2. and 3.:
5. this equation only has one unknown and can be solved for v:
Answer:
Explanation:
ω =
k = 2.5 N/m
m = 10 kg
ω = .5 rad /s
x(t) = A cos(ωt + φ₀)
When t = 0 , x(t) = 0
0 = A cos(ωx 0 + φ₀)
cos φ₀ = 0
φ₀ = π /2
x(t) = A cos(ωt +π /2 )
Putting the value of ω
x(t) = A cos(.5 t +π /2 )
Differentiating on both sides
dx(t)/dt = - .5 A sin(.5 t +π /2 )
v(t) = - .5 A sin(.5 t +π /2 )
Given t =0 , v(t) = -5 m/s
-5 = - .5 A sin(.5 x0 +π /2 )
-5 = - .5 A sinπ /2
A = 10 m
x(t) = 10 cos( .5 t +π /2 )
b )
when t = π ( 3.14 s )
x(t) = - 10 m
when t = 2π ( 6.28s )
x(t) = 0
when t = 3π ( 9.42 s )
x(t) = 10 m
and so on