Answer:
False statement = There must be a non-zero net force acting on the object.
Explanation:
An object is moving at a constant speed along a straight line. If the speed is constant then its velocity must be constant. We know that the rate of change of velocity is called acceleration of the object i.e.
a = 0
⇒ The acceleration of the object is zero.
The product of force and acceleration gives the magnitude of force acting on the object i.e.
F = m a = 0
⇒ The net force acting on the object must be zero.
So, the option (a) is not true. This is because the force acting on the object is zero. First option contradicts the fact.
Answer:
Explanation:
The specific gravity is given by,
Now, in order to calculate the uncertainty (relative error) in G, we must first take log (base e) on both sides of the equation,
Differentiating the above equation,
The second term is zero because it is known that and hence a constant.
Putting the appropriate values, we get,
Therefore, uncertainty in G =
Answer:
Explanation:
The question says that, "The closest star to the earth is 2 light years away. Calculate this distance in SI units".
Given that,
The distance between the closest star and the Earth is 2 light years.
The SI unit of distance is m. It means we need to convert light years to meters. We know that,
2 light-years means,
So, the required distance is equal to .