Answer:
Car first should be 30.13 m behind the second car.
Explanation:
Given that,
Constant speed = 108.5 Km/hr
Time = 1 sec
Let the distance covered by second car S and by first car S'
We need to calculate the distance covered by second car
Using equation of motion
.....(I)
The distance covered by first car to avoid collision
Put the value into the formula
...(II)
We need to calculate the distance covered by first car
Using equation (I) and (II)
Put the value into the formula
Hence, Car first should be 30.13 m behind the second car.
Answer:
No
Explanation:
Our universe is not the size of a grain of sand. A grain of sand is approximately 2 millimeters while the size of the universe is approximate 93 billion light years in diameter and recently estimated to be 250 times 93 billion light years which is at least 7 trillion light years.
Light-year is a unit of length used to show astronomical distances.
1 light-year is exactly 9460730472580800 meters.
Comparing the size of a grain of sand to that of the universe,
2 millimeters = 0.002 meters and
9460730472580800 meters = 9.460730472580800 e+18
You can't change time to a measurement of distance
Answer:
v=2.45 m/s
Explanation:
The rotational kinetic energy is calculated with:
The moment of inertia of a disk is:
A point on the rim of a disk will have a speed of:
Putting all together:
Which for our values is:
Answer:
A) and B) are correct.
Explanation:
If the object is at rest, it means that no net force is exerted on it.
As the object experiences a downward gravitational force from Earth, in order to be at rest, it must experience an upward force with the same magnitude as the gravitational force on the object.
This force is supplied by the normal force, which can adopt any value in order to meet the condition imposed by Newton´s 2nd Law, and is always perpendicular to the surface on which the object is placed (in this case, the ground).
At a molecular level, this normal force is supplied by the bonded molecules of the ground that behave like small springs being compressed by the molecules of the object, exerting an upward restoring force upward on them.
So, the statements A) and B) are true.
