Answer: option A. r = 3x+2y
Explanation:
Vector r is plotted on the graph. On x-axis each small division corresponds to 1 unit. Similarly on y-axis, each small division corresponds to one unit.
The vector is the resultant of addition of its x and y components. we would draw perpendicular to the x-axis and y-axis from the head of vector r.
On x-axis, = +3 units
on y-axis, = +2 units
Hence, vector r can be written as: r = 3x + 2y . Correct option is A.
Explanation :
It is given that, a heavy box is in the back of a truck and the truck is accelerating to the right.
The description is shown in<em> figure 1</em>. Here, the forces that act on both box and the truck are the normal force, the frictional force and their weight mg.
The free body diagram is shown in <em>figure 2</em>. This shows the total forces ( F = ma )acting on the truck. As a result, the truck will move in a forward direction.
Hence, this is the required explanation.
If two people hit identical tennis balls at the same time, the ball that has the most kinetic energy is the ball that moves at the fastest speed.
<u>Explanation:</u>
The energy possessed by an object by virtue of its motion is called its kinetic energy indicating that only moving objects have kinetic energy. The kinetic energy of an object depends on its speed and mass.
It is given by the expression
where m denotes the mass of the object and v denotes its velocity.
since kinetic energy is directly proportional to the square of the velocity, the kinetic energy of an object increases with its velocity.
Hence an object that moves at the fastest speed will have the most kinetic energy.