Answer:
The velocity of the truck after the collision is 20.93 m/s
Explanation:
It is given that,
Mass of car, m₁ = 1200 kg
Initial velocity of the car, 
Mass of truck, m₂ = 9000 kg
Initial velocity of the truck, 
After the collision, velocity of the car, 
Let
is the velocity of the truck immediately after the collision. The momentum of the system remains conversed.




So, the velocity of the truck after the collision is 20.93 m/s. Hence, this is the required solution.
Answer:
I = 2 kgm^2
Explanation:
In order to calculate the moment of inertia of the door, about the hinges, you use the following formula:
(1)
I: moment of inertia of the door
α: angular acceleration of the door = 2.00 rad/s^2
τ: torque exerted on the door
You can calculate the torque by using the information about the Force exerted on the door, and the distance to the hinges. You use the following formula:
(2)
F: force = 5.00 N
d: distance to the hinges = 0.800 m
You replace the equation (2) into the equation (1), and you solve for α:

Finally, you replace the values of all parameters in the previous equation for I:

The moment of inertia of the door around the hinges is 2 kgm^2
F=ma
m=total mass = 2300kg+2500kg=4800
F=18000N
a=?
a=F/m
a=18000/4800
a=3.8m/s^2
Final answer
Answer with Explanation:
We are given that
Radius of solid core wire=r=2.28 mm=

Radius of each strand of thin wire=r'=0.456 mm=
Current density of each wire=
a.Area =
Where 
Using the formula
Cross section area of copper wire has solid core =
Current density =
Using the formula


Total number of strands=19
Area of strand wire=




b.Resistivity of copper wire=
Length of each wire =6.25 m
Resistance, R=
Using the formula
Resistance of solid core wire=
Resistance of strand wire=
Answer:
0.775
Explanation:
The weight of an object on a planet is equal to the gravitational force exerted by the planet on the object:

where
G is the gravitational constant
M is the mass of the planet
m is the mass of the object
R is the radius of the planet
For planet A, the weight of the object is

For planet B,

We also know that the weight of the object on the two planets is the same, so

So we can write

We also know that the mass of planet A is only sixty percent that of planet B, so

Substituting,

Now we can elimanate G, MB and m from the equation, and we get

So the ratio between the radii of the two planets is
