We're given the velocity at two points, and the time between the mentioned two points.
What we'll be calculating is the average acceleration (not to be confused with instantaneous acceleration).
Given two points, lets call them initial and final, the average acceleration is calculated as:
In which
is the final velocity (in your problem equal to 1m/s),
is the initial velocity (in your problem equal to 16 m/s), and
the time between two points (in your problem equal to 2s).
So, we plug-in our known values:
The answer is -7.5m/s^2.
For part a)
Since the conical surface is not exposed to the radiation coming from the walls only from the circular plate and assuming steady state, the temperature of the conical surface is also equal to the temperature of the circular plate. T2 = 600 K
For part b)
To maintain the temperature of the circular plate, the power required would be calculated using:
Q = Aσ(T₁⁴ - Tw⁴)
Q = π(500x10^-3)²/4 (5.67x10^-8)(600⁴ - 300⁴)
Q = 5410.65 W
It is gravity¿ what is the question?
- mechanical energy is conserved in all the listed situations
- true
- potential energy
- 490 J
- 750,000 J
EXPLANATION
1. sum of kinetic energy (KE) and potential energy (PE) is known as mechanical energy
- kinetic energy is the motion of an object
- potential energy is the position of an object
there is kinetic energy and other energies in the listed situation.
2. since the height decreases due to the fall, the potential energy also decreases but the speed increases and kinetic energy simultaneously increases so the potential energy is converted to kinetic energy.
3.the energy consumed by an object due to its position is known as potential energy
4. potential energy
PE = m g h
m = 10 kg mass of the object
g = 9.8 m/s^2 acceleration of gravity
h= 5 m height of the object from ground
substituting every value in the formula
PE = (10)(9.8)(5)
PE= 490 J
5. potential energy
PE = m g h
but given is the weight and the height of the elevator
W= 1500 N
h= 500 m
but weight of the object is equal to the product of acceleration of gravity and mass of the elevator
so, W = mg
so we can rewrite the formula as PE = Wh
PE = (1500)(500)
PE= 750,000 J