a block is dragged without acceleration in a straight-line path across a level surface by a force of 6N. what is the frictional
1 answer:
The frictional force between the block and the surface is 6 N
Explanation:
We can solve this problem by applying Newton's second law of motion, which states that the net force on an object is equal to the product between its mass and its acceleration:
where
is the net force
m is the mass
a is the acceleration
For the block in this problem, we have:
, because its acceleration is zero
, since the net force is given by the difference between the applied force
(in the forward direction) and the frictional force
(in the backward direction)
Therefore Newton's second law becomes
Which means
And since the applied force is , this means that the friction force is also 6 N:
Learn more about friction:
#LearnwithBrainly
You might be interested in
(a)
At a distance r=R from the centre of the planet, there is no effect due to the outer shell: so, the gravitational field strength at r=R is only determined by the gravity produced by the core of the planet.
So, the strength of the gravitational field is given by
where
G is the gravitational constant
M = 6.24 × 10^24 kg is the mass of the core of the planet
R = 4.11 × 10^6 m is the radius of the core
Substituting into the equation, we find
(b)
at distance r=3R from the centre, the particle feels the effect of gravity due to both the core of the planet and the outer shell between R and 2R.
So, we have to consider the total mass that exerts the gravitational attraction at r=3R, which is the sum of the mass of the core (M) and the mass of the shell (4M):
M' = M + 4M = 5M
Therefore, the gravitational acceleration at r=3R will be
And susbstituting
g = 24.6 m/s^2
found in the previous part, we find