Gravity<span> is measured by the acceleration that it gives to freely falling objects. At Earth's surface the acceleration of </span>gravity<span> is about 9.8 metres (32 feet) per second per second.</span>
We will apply the conservation of linear momentum to answer this question.
Whenever there is an interaction between any number of objects, the total momentum before is the same as the total momentum after. For simplicity's sake we mostly use this equation to keep track of the momenta of two objects before and after a collision:
m₁v₁ + m₂v₂ = m₁v₁' + m₂v₂'
Note that v₁ and v₁' is the velocity of m₁ before and after the collision.
Let's choose m₁ and v₁ to represent the bullet's mass and velocity.
m₂ and v₂ represents the wood block's mass and velocity.
The bullet and wood will stick together after the collision, so their final velocities will be the same. v₁' = v₂'. We can simplify the equation by replacing these terms with a single term v'
m₁v₁ + m₂v₂ = m₁v' + m₂v'
m₁v₁ + m₂v₂ = (m₁+m₂)v'
Let's assume the wood block is initially at rest, so v₂ is 0. We can use this to further simplify the equation.
m₁v₁ = (m₁+m₂)v'
Here are the given values:
m₁ = 0.005kg
v₁ = 500m/s
m₂ = 5kg
Plug in the values and solve for v'
0.005×500 = (0.005+5)v'
v' = 0.4995m/s
v' ≅ 0.5m/s
Answer:
Option (C)
Explanation:
From Newton's law of inertia, an object at rest tends to be at rest until there is an external force applied to it.
In the given question, the rock block that fell on the road due to the avalanche contains high mass and high inertia. Due to which the block was not able to move aside. <u>The amount of energy required to push the block aside should be more than the mass of the block</u>. So the block has high inertia value and it will need more force than its inertia value in order to move the block of rock towards the side of the road.
Thus, the correct answer is option (C).
Acceleration = (change in speed) / (time for the change)
Acceleration = (4 m/s) / (8 seconds)
Acceleration = 0.5 m/s²
Force = (mass) x (acceleration)
Force = (85 kg) x (0.5 m/s²)
Force = 42.5 Newtons
