Answer:
A) 1000 joules
Explanation:
In general work is given by the equation:
(1)
A) With
the displacement and
the force applied, because the force and the displacement are parallel (the crate is pushed horizontally)
is simply
, and because the path is a straight line and the force is constant work is:
(2),

B) The work-energy theorem says that the total work on a body is equal to the change on kinetic energy:
(3)
The total work on the crate is the work done by the push and plus the work of the friction
(4) , as (A) because forces are parallel to the displacement
(5) and
(6), the due friction always has negative sign because is opposite to the displacement, using (6), (5) and (4) on (3):
(3)
C) The energy is lost by friction, so the amount of energy turned into heat is the work the friction does:
(3)
1. For the first one if it doesn't shatter then it is hard.
2. We sould consider that room temperature is usuall<span>y from 18°C (64°F) to 23°C (73°F) and since the melting point of the substance is 40˚C the substance is liquid, because is melting point not an evaporation point it just melts from solid to liquid.
3. Well, in this one we have to consider that a chemical change it change the thing completely. So in this case is baking a cake because the products make the cake stop being them self and created something else.
4. It tends to have low reactivity. This is because viscosity means something like honey very sticky<span> ,</span> density is how hard it is and lastly the conductivity I would believe is to pass electricity or current.
5. It is a physical change because the evaporated water transforms again into water and then fall as rain, snow or ice.
Hope it helped <3</span>
Angular frequency of pendulum is given by

for both pendulum we have


For other pendulum


now we have relate angular frequency given as
[tex\omega_1 - \omega_2 = 3.13 - 2.98 = 0.15 rad/s[/tex]
now time taken to become in phase again is given as


now number of oscillations complete in above time



Answer:
The correct answer is option B.
Explanation:

f = focal length
P = -5.5 D (negative power means that lens is concave)

1 m = 100 cm
f = -0.1818 m = -0.1818 × 100 cm= -18.18 cm



v = -18.18 cm
v = 1.8 cm - far point
far point = 1.8 cm - v =1.8 cm - (-18.18 cm) = 19.98 cm
But closest answer from the given options is option B.Hence, 20 cm is the correct answer.
Answer:
it's D
Explanation:
by asking your teacher how he/she thinks about you