The brakes in a car increase in temperature by
$\text{\Delta}T$ when bringing the car to rest from a speed
$v$ . How much greater would
$\text{\Delta}T$ be if the car initially had twice the speed? You may assume the car to stop sufficiently fast so that no heat transfers out of the brakes.
On a hot day, the temperature of an 80,000-L swimming pool increases by
$1\text{.}\text{50\xbaC}$ . What is the net heat transfer during this heating? Ignore any complications, such as loss of water by evaporation.
To sterilize a 50.0-g glass baby bottle, we must raise its temperature from
$\text{22}\text{.}0\text{\xbaC}$ to
$\text{95}\text{.}\mathrm{0\xba}\text{C}$ . How much heat transfer is required?
The same heat transfer into identical masses of different substances produces different temperature changes. Calculate the final temperature when 1.00 kcal of heat transfers into 1.00 kg of the following, originally at
$\text{20}\text{.}\mathrm{0\xba}\text{C}$ : (a) water; (b) concrete; (c) steel; and (d) mercury.
Rubbing your hands together warms them by converting work into thermal energy. If a woman rubs her hands back and forth for a total of 20 rubs, at a distance of 7.50 cm per rub, and with an average frictional force of 40.0 N, what is the temperature increase? The mass of tissues warmed is only 0.100 kg, mostly in the palms and fingers.
A 0.250-kg block of a pure material is heated from
$\text{20}\text{.}\mathrm{0\xba}\text{C}$ to
$\text{65}\text{.}\mathrm{0\xba}\text{C}$ by the addition of 4.35 kJ of energy. Calculate its specific heat and identify the substance of which it is most likely composed.
Suppose identical amounts of heat transfer into different masses of copper and water, causing identical changes in temperature. What is the ratio of the mass of copper to water?
(a) The number of kilocalories in food is determined by calorimetry techniques in which the food is burned and the amount of heat transfer is measured. How many kilocalories per gram are there in a 5.00-g peanut if the energy from burning it is transferred to 0.500 kg of water held in a 0.100-kg aluminum cup, causing a
$\text{54}\text{.}\mathrm{9\xba}\text{C}$ temperature increase? (b) Compare your answer to labeling information found on a package of peanuts and comment on whether the values are consistent.
Following vigorous exercise, the body temperature of an 80.0-kg person is
$\text{40}\text{.}\mathrm{0\xba}\text{C}$ . At what rate in watts must the person transfer thermal energy to reduce the the body temperature to
$\text{37}\text{.}\mathrm{0\xba}\text{C}$ in 30.0 min, assuming the body continues to produce energy at the rate of 150 W?
$\left(\text{1 watt = 1 joule/second or 1 W = 1 J/s}\phantom{\rule{0.25em}{0ex}}\right)$ .
Even when shut down after a period of normal use, a large commercial nuclear reactor transfers thermal energy at the rate of 150 MW by the radioactive decay of fission products. This heat transfer causes a rapid increase in temperature if the cooling system fails
$(\text{1 watt = 1 joule/second or 1 W = 1 J/s and 1 MW = 1 megawatt})$ . (a) Calculate the rate of temperature increase in degrees Celsius per second
$(\text{\xbaC/s})$ if the mass of the reactor core is
$1\text{.}\text{60}\times {\text{10}}^{5}\phantom{\rule{0.25em}{0ex}}\text{kg}$ and it has an average specific heat of
$\text{0.3349 kJ/kg\xba}\cdot \text{C}$ . (b) How long would it take to obtain a temperature increase of
$\text{2000\xba}\text{C}$ , which could cause some metals holding the radioactive materials to melt? (The initial rate of temperature increase would be greater than that calculated here because the heat transfer is concentrated in a smaller mass. Later, however, the temperature increase would slow down because the
$5\times {\text{10}}^{5}\text{-kg}$ steel containment vessel would also begin to heat up.)
Calculate the work done by an 85.0-kg man who pushes a crate 4.00 m up along a ramp that makes an angle of 20.0º20.0º with the horizontal. (See [link] .) He exerts a force of 500 N on the crate parallel to the ramp and moves at a constant speed. Be certain to include the work he does on the crate an
static fiction is friction between two surfaces in contact an none of sliding over on another, while Kinetic friction is friction between sliding surfaces in contact.
MINDERIUM
I don't get it,if it's static then there will be no friction.
author
It means that static friction is that friction that most be overcome before a body can move
kingsley
static friction is a force that keeps an object from moving, and it's the opposite of kinetic friction.
author
It is a force a body must overcome in order for the body to move.
Eboh
If a particle accelerator explodes what happens
Eboh
why we see the edge effect in case of the field lines of capacitor?
Force equals mass time acceleration. Weight is a force and it can replace force in the equation. The acceleration would be gravity, which is an acceleration. To change from weight to mass divide by gravity (9.8 m/s^2).
the write question should be " How many Topics are in O- Level Physics, or other branches of physics.
effiom
how many topic are in physics
Praise
Praise what level are you
yusuf
If u are doing a levels in your first year you do AS topics therefore you do 5 big topic i.e particles radiation, waves and optics, mechanics,materials, electricity. After that you do A level topics like Specific Harmonic motion circular motion astrophysics depends really
Anya
Yeah basics of physics prin8
yusuf
Heat nd Co for a level
yusuf
yh I need someone to explain something im tryna solve . I'll send the question if u down for it
a ripple tank experiment a vibrating plane is used to generate wrinkles in the water .if the distance between two successive point is 3.5cm and the wave travel a distance of 31.5cm find the frequency of the vibration
Tamdy
hallow
Boniface
please send the answer
Boniface
the range of objects and phenomena studied in physics is