Answer:
Diverging lens
Explanation:
Given parameters:
Power of lens = -2.0D
Unknown:
Focal length = ?
Solution:
The power of lens is the reciprocal of the focal length;
P =
where f is the focal length
f =
=
The lens is a diverging lens
Answer:
Explanation:
Projectile Motion. Projectile motion is different than free fall: it involves two dimensions instead of one. ... Balls traveling in two dimensions, only one of which experiences acceleration, require two sets of equations: one set for the x-direction and the other for the y-direction.
Answer:

Explanation:
given,
length of the ship = 120 m
length of model of the ship = 4 m
Speed at which the ship travels = 70 km/h
speed of model = ?
by using froude's law

for dynamic similarities




hence, the velocity of model will be 12.78 km/h
Answer:
The equatiom of kinetic energy is 1/2×m×v² where m represents mass and v is velocity :

The unit for kinetic energy is measured in Joules (J).
Answer:
3099 J
Explanation:
The increase in thermal energy corresponds to the mechanical energy lost in the process.
The mechanical energy is given by the sum of gravitational potential energy and kinetic energy of the fireman:

At the top of the pole, the fireman has no kinetic energy, so all his mechanical energy is just potential energy:

When the fireman reaches the bottom, he has no gravitational potential energy, so his mechanical energy is just given by his kinetic energy:

So, the loss in mechanical energy was

and this corresponds to the increase in thermal energy.