Answer:
35%
Explanation:
The car's engine gives off 65% thermal energy
So only 35 % is converted into mechanical energy .
input heat = Q₁ = 100
output heat = Q₂ = 65
Work output = Q₁ - Q₂ = W
W = 100 - 65 = 35
Efficiency = W / Q₁ X 100
= (35/ 100) X 100
= 35%.
Answer:
Bears lose necessary body fat because they must swim longer in open ocean water.
Explanation:
Polar bears, like their cousins, the grizzly bears, must build up a store of body fat that they can live off of during the winter months. This is especially true of mother bears who give birth to cubs during this time and need enough nourishment to feed the cubs.
(can i have brainliest please?)
Answer:
t = 0.28 seconds
Explanation:
Given that,
Force acting on a firework, F = 700 N
The momentum of the firework, p =200 kg-m/s
We need to find the time before it explodes. Ket the time be t. We know that, the rate of change of momentum is equal to external frce. So,
So, the required time is equal to 0.28 seconds.
The apple in my hand has three different forms of energy
that I can think of.
1). Thermal energy. I know that the apple's temperature is
not absolute zero, because it is not freezing my hand off.
Therefore it holds some heat energy.
2). Chemical energy. From previous experience, I know that
if I eat the apple, it gives me a boost and keeps the doctor away,
since my body is able to metabolize it, and extract nutrition from
its chemical energy.
3). Potential energy. Also from previous experience, I realize
that when I picked up the apple, I exerted force on it opposite to
the force of gravity. By doing work on it, I endowed it with increased
gravitational potential energy, which would immediately be obvious
if I dropped it to the ground, where it would either smash or dig a
little crater in the grass.
Answer:
Explanation:
When the space is filled with dielectric, an induced opposite sign charge appears on each surface of the dielectric. This induced charge has a charge density related to the charge density on the electrodes as follows:
Where E is the eletric field with dielectric and 
is the electric filed without it. Recall that 
is given by:
Replacing this and solving:
