Answer:
The net force = 0
Explanation:
The given information includes;
The mass of the crate = 250 kg
The way the helicopter lifts the crate = Uniformly (constant rate (speed), no acceleration)
In order to pull the crate upwards, the helicopter has to provide a force equivalent to the weight of the crate keeping the helicopter on the ground.
The weight of the crate = The mass of the crate × The acceleration due gravity acting on the crate
The weight of the crate, 
↓ = 250 kg × 9.81 m/s² = 2,452.5 N
The force the helicopter should provide to just lift the crate, 
↑ = The weight of the crate = 2,452.5 N
The net force, 
= ↑ - ↓ = 2,452.5 N - 2,452.5 N = 0
The net force = 0.
Answer: 115.2kg
Explanation:
Net force = 265 N
Acceleration of bike & rider = 2.30m/s2 (The SI unit of acceleration is m/s2)
Mass of the bike and rider together = ?
Since force is the product of the mass of an object and the acceleration by which it moves, Force = Mass x Acceleration
265N = Mass x 2.30m/s2
Mass = (265N/2.30m/s2)
Mass = 115.2 kg
Thus, the Mass of the bike and rider together is 115.2kg
Answer:
The correct option is;
Raymond: I think the skateboarder has the same total energy at all points on the ramp
Explanation:
The total energy, also known as the total mechanical energy, is the sum of the kinetic and potential energies of the skateboarder
Given that the potential energy is the energy gained due to elevation, the maximum potential energy is obtained at the top of the ramp, while the maximum kinetic energy, which is the energy due to motion, is at the bottom of the ramp where the skateboarder moves fastest.
However, by the energy conservation principle, the kinetic energy of he skateboarder comes from the conversion of the potential energy, such that the total energy is the same at any particular point on the ramp.
First we need to find the acceleration of the skier on the rough patch of snow.
We are only concerned with the horizontal direction, since the skier is moving in this direction, so we can neglect forces that do not act in this direction. So we have only one horizontal force acting on the skier: the frictional force,
. For Newton's second law, the resultant of the forces acting on the skier must be equal to ma (mass per acceleration), so we can write:
Where the negative sign is due to the fact the friction is directed against the motion of the skier.
Simplifying and solving, we find the value of the acceleration:
Now we can use the following relationship to find the distance covered by the skier before stopping, S:
where
is the final speed of the skier and
is the initial speed. Substituting numbers, we find:
