Answer:
Mercury is the smallest planet, but its surface gravity is about the same as that of the larger Mars, because Mercury is denser. As such, Saturn is much larger than Earth, but not very dense, so the gravity on Saturn is roughly the same as on Earth. Mars: 0.38 G. Jupiter: 2.53 grams.
Whenever a vehicle is in motion, it has got kinetic energy. Kinetic energy has a direct relationship with the stopping distance. Kinetic energy is dependent on the mass of the vehicle and also the velocity at which it is traveling. In case of a small vehicle, the mass of the vehicle will be small and so the stopping distance will also be less compared to a large vehicle. In the case of the large vehicle traveling at the same velocity as the small vehicle, the stopping distance will be greater because the large vehicle has a larger mass. So in case of a small vehicle the kinetic energy will be less and so the distance for stopping will be less than that of the large vehicle.
Answer:
the correct statement is 2. The solid plate will have the greater angular acceleration.
the correct phrase is 4. The plate with the hole has its mass distributed further out from the axis of rotation, which will increase its moment of inertia.
Explanation:
Newton's second law expression for rotational motion is
τ = I α (1)
where the torque is
τ = F r
in this case, as the discs have the same radius and the applied force is the same, the torque is the same on the two discs.
The moment of inertia is given by the expression
I =∫ r² dm
for bodies with high symmetry are tabulated
the moment of inertia for in disk solid is I₁ = ½ m R₂²
the moment for a disk with a hole I₂ = ½ m (R₁² + R₂²)
We can see that the moment of inertia of the disk with the hole is greater than the moment of inertia of the solid disk.
Let's use equation 1
α = τ/I
therefore the angular acceleration is lower for the body with the higher moment of inertia, consequently the solid disk has higher angular acceleration
the correct statement is 2
The reason is because the moment of inertia is higher for the hollow disk.
the correct phrase is 4
Answer:
the acceleration of the girl is 8 m/s² in opposite direction.
Explanation:
Given;
mass of the girl, m₁ = 30kg
mass of the boy, m₂ = 40 kg
acceleration of the boy, a₂ = 6 m/s²
let acceleration of the girl = a₁
Apply Newton's third law of motion;
the force exerted by the girl is equal in magnitude to the force exerted by the boy but in opposite direction.
F₁ = -F₂
m₁a₁ = -m₂a₂
30a₁ = -(40 x 6)
30a₁ = -240
a₁ = -240 / 30
a₁ = -8 m/s² (the negative sign shows that the acceleration is in opposite direction)
Thus, the acceleration of the girl is 8 m/s² in opposite direction.
To solve any problem in math or physics, you collect all the formulas,
laws, rules, and equations that you know about the subject, then, along
with the given information, use them to find the missing information.
So the answer to "how" really depends on what information you're given.