<span>a+b= ?
3i +3j + (3i -3j) = ?
3i + 3j + 3i -3j =?
= 6i + 0j</span>
Options A and D are correct. The strength of the force of friction depends on the objects' sizes and weights and the heat generated by the friction and the types of surfaces involved.
<h3 /><h3>What is the friction force?</h3>
It is a type of opposition force acting on the surface of the body that tries to oppose the motion of the body. its unit is Newton (N).
Mathematically, it is defined as the product of the coefficient of friction and normal reaction.
On resolving the given force and acceleration in the different components and balancing the equation gets. Components in the x-direction.
The strength of the force of friction depends on the two factors, as;
A. The objects' sizes and weights.
D. The heat generated by the friction and the types of surfaces involved.
Hence, options A and D are correct.
To learn more about the friction force, refer to the link;
brainly.com/question/1714663
#SPJ1
Answer:

Explanation:
The time lag between the arrival of transverse waves and the arrival of the longitudinal waves is defined as:

Here d is the distance at which the earthquake take place and
is the velocity of the transverse waves and longitudinal waves respectively. Solving for d:

Answer:
The angular magnification is 
Explanation:
From the question we are told
The focal length is 
The near point is 
The angular magnification is mathematically represented as

Substituting values

Answer:
- magnitude : 1635.43 m
- Angle: 130°28'20'' north of east
Explanation:
First, we will find the Cartesian Representation of the
and
vectors. We can do this, using the formula

where
its the magnitude of the vector and θ the angle. For
we have:


where the unit vector
points east, and
points north. Now, the
will be:

Now, taking the sum:

This is




Now, for the magnitude, we just have to take its length:



For its angle, as the vector lays in the second quadrant, we can use:



