Answer:

Explanation:
Since the package remains in contact with the car's seat, the package's speed is equal to the car's speed. At the top on the mountain the package's centripetal force must be equal to its weight:

The centripetal force is defined as:

Here v is the linear speed of the object and r is the radius of curvature. We need to convert the linear speed to
:

Now, we calculate r:

Mass is the amount of matter in an object whereas weight is the force of gravity acting on the mass of an object. Different planets exert a different force of gravity on an object-meaning that an object's weight will change depending on the force of gravity acting on it, but it's mad will remain unchanged.
Answer:
the mass of the truck is 2 kg.
Explanation:
Given;
mass of the car, m₁ = 3 kg
initial velocity of the car, u₁ = 40 m/s
initial velocity of the truck, u₂ = 60 m/s
let the mass of the truck = m₂
Apply the principle of conservation of linear momemtum;
m₁u₁ = m₂u₂
m₂ = (m₁u₁) / u₂
m₂ = (3 x 40) / (60)
m₂ = 2 kg
Therefore, the mass of the truck is 2 kg.