Without friction, NO.
The speed at D depends only on the difference in height between A and D. Whatever happens between them doesn't matter.
Answer:
The answer is convection.
Explanation:
There are three types of heat transfer: conduction, convection and radiation.
- Conduction occurs when two objects touch each other and transfer heat.
- Convection occurs when an object heats its surrounding fluid (like air, or water) and, since the hot fluids are less dense than the cold ones, they go up. So convection is a type of heat transfer that usually goes from down to up.
- Radiation occurs when objects emanate heat in the form of electromagnetic waves that propagates in all directions.
So in this case, when the marshmallow is above the fire, it is exposed to convection, which does not occur when it is on the side of the fire.
Answer:
a)1.13×10³
b)1.6×10³
Explanation:
Given:
Boltzmann's constant (K)=1.38×10^-23 J/K
atmoic mass of helium = 4 AMU or 4×1.66×10^-27kg
a)The formula for RMS speed (Vrms) is given as
where
K= Boltzmann's constant
T= temperature
m=mass of the gas
b) RMS speed of helium when the temperature is doubled
Answer:
Force exerted on the car is 7030 N.
Explanation:
It is given that,
Mass of the car, m = 740 kg
Initial speed of the car, u = 19 m/s
Final speed of the car, v = 0
Time taken, t = 2 s
Let F is the force exerted on the car during this stop. We know that it is equal to the product of force and acceleration. Mathematically, it is given as :
F=m\times \dfrac{v-u}{t}F=m×tv−u
F=740\times \dfrac{0-19}{2}F=740×20−19
F = -7030 N
So, the force exerted on the car during this stop is 7030 N. Hence, this is the required solution.