answer;
The hole in the center of the washer will expand
explanation;
<em>A flat metal washer is heated. As the washer's temperature increases, what happens to the hole in the center? A flat metal washer is heated. As the washer's temperature increases, what happens to the hole in the center? The hole in the center will remain the same size. Changes in the hole cannot be determined without know the composition of the metal. The hole in the center of the washer will expand. The hole in the center of the washer will contract.</em>
this is an example of area expansivity.
coefficient of area expansivity is change in area per area per degree rise in temperature
a=dA/(A*dt)
as the temperature rises , there will be volumetric and area expansivity on the body. volume also increases because of the intermolecular forces of attraction between the molecule is now getting apart.
Answer:
6 s
Explanation:
given,
Sports car accelerate from 0 to 30 mph in 1.5 s
time taken to accelerate 0 to 60 mph = ?
The power of the engine is independent of velocity and neglecting friction
power =
P = constant
the kinetic energy for 60 mph larger than this of 30 mph
= 
= 
= 
= 4
gain in kinetic energy = P x t
time = 4 x 1.5
= 6 s
Effect of temperature.
"If the temperature of the substance is increased then the rate of chemical reaction is also increased because the kinetic energy is greater."
Effect of surface area.
"If the surface area is increased then the rate of reaction is increased because there will be more active sites for the reaction to occur.
Answer:
- 1 m/s, 20 m
Explanation:
u = 9 m/s, a = - 2 m/s^2, t = 5 sec
Let s be the displacement and v be the velocity after 5 seconds
Use first equation of motion.
v = u + a t
v = 9 - 2 x 5 = 9 - 10 = - 1 m/s
Use second equation of motion
s = u t + 1/2 a t^2
s = 9 x 5 - 1/2 x 2 x 5 x 5
s = 45 - 25 = 20 m
