Answer:
f = - 0.143 m = - 14.3 cm
Explanation:
First, we will calculate the power of the combination of lenses:
P = P₁ + P₂
where,
P = Power of Combination = ?
P₁ = Power of first lens = - 5D
P₂ = Power of second lens = - 2D
Therefore,
P = - 5D - 2D
P = - 7D
Now, the focal length can be given as:
<u>f = - 0.143 m = - 14.3 cm</u>
Negative focal length indicates that combination will act as diverging lens.
Answer: Friction
Explanation:
Friction is a force that opposes the motion of an object on another surface. For example, when a box is pushed along the floor, the floor exerts a frictional force on the box, "resisting" the motion of the box. This force is due to the contact between the molecules of the box and the molecules of the floor, and it is always directed against the direction of motion of the object (so, if the object is moving forward, friction acts backwards).
The magnitude of the friction force is given by:
where is the coefficient friction, which is a number that depends on the materials of the two surfaces, and N is the normal reaction.
Answer:
The Statement is wrong because the reverse is the case as it is the kinetic energy that is being transformed to gravitational potential energy.
Explanation:
As your friend throws the baseball into the air the ball gains an initial velocity (u) and this makes the Kinetic energy to be equal to
Here m is the mass of the baseball
Now as this ball moves further upward the that velocity it gained reduce due to the gravitational force and this in turn reduces the kinetic energy of the ball and this kinetic energy lost is being converted to gravitational potential energy which is mathematically represented as (m×g×h)
as energy can not be destroyed but converted to a different form according to the first law of thermodynamics
Looking a the formula for gravitational potential energy we see that the higher the ball goes the grater the gravitational potential energy.