Answer:
v = 27 m/s
Explanation:
To find the speed of cars after the collision you take into account the momentum conservation law. Total momentum of both cars before the collision must be equal to the total momentum of both cars after the collision.
After the collision both cars traveled together, then you have:
(1)
m1: mass of the Toyota = 3-ton = 3000 kg
m2: mass of the taxi = 2-ton = 2000kg
v1: speed of the Toyota before the collision = 45m/s
v2: speed of the car before the collision = 0 m/s (it is at rest)
v: speed of both cars after the collision = ?
You solve the equation (1) for v:
Next, you replace the values of the rest of the variables:
hence, just after the collision both cars have a speed of 27m/s
It is because change in the Mass of the object balances the change in the Volume of the object equally...........
Answer:
ΔD = 2.29 10⁻⁵ m
Explanation:
This is a problem of thermal expansion, if the temperature changes are not very large we can use the relation
ΔA = 2α A ΔT
the area is
A = π r² = π D² / 4
we substitute
ΔA = 2α π D² ΔT/4
as they do not indicate the initial temperature, we assume that ΔT = 75ºC
α = 1.7 10⁻⁵ ºC⁻¹
we calculate
ΔA = 2 1.7 10⁻⁵ pi (1.8 10⁻²) ² 75/4
ΔA = 6.49 10⁻⁷ m²
by definition
ΔA = A_f- A₀
A_f = ΔA + A₀
A_f = 6.49 10⁻⁷ + π (1.8 10⁻²)² / 4
A_f = 6.49 10⁻⁷ + 2.544 10⁻⁴
A_f = 2,551 10⁻⁴ m²
the area is
A_f = π D_f² / 4
A_f = 
D_f = 
D_f = 1.80229 10⁻² m
the change in diameter is
ΔD = D_f - D₀
ΔD = (1.80229 - 1.8) 10⁻² m
ΔD = 0.00229 10⁻² m
ΔD = 2.29 10⁻⁵ m
Time = (distance) / (speed)
Distance = 3,000 km = 3,000,000 meters
Speed = 200 m/s
Time = (3,000,000 m) / (200 m/s)
Time = <em>15,000 seconds</em>
That's 4 hours 10 minutes
Answer:
(km/mins) × ( mins/hr) = km/hr
(10/10)×(60/1) =600/10 = 60 km /hr
......
