Work done is given by the change in kinetic energy of an object
- The kinetic energy of the shovel, the shrub, and in Robert's movement were changed, therefore, work is done in the given processes,
Reason:
Work is done when the total energy of object is affected by the application of force on the object over a distance
Therefore;
- In option <em>A</em>, pushing the shovel into ground (to dig out the dirt) the requires the application of a force (push) over a distance, (into and out of the ground) therefore work is done
- In option <em>B</em>, picking the shrub up gives it gravitational potential energy, therefore, work is done
- In option <em>C</em>, carrying the shrub to the hole does visible work
- In option <em>D</em>, holding the shrub while lowering it into the hole does work by preventing the shrub from falling randomly
Therefore, <u>work is done in the given processes</u>
Learn more about work-energy theorem here:
brainly.com/question/10063455
Answer:
40 j, 80j.
Explanation:
P.E= mgh. G=10 m/s².
For 4m, P.E=1*10*4=40 joules.
For 8m, P.E=1*10*8=80 joules.
Complete Question
A voltaic cell is constructed with two 
electrodes. The two cell compartment have ![[Zn^{2+}] = 1.6 \ M](https://tex.z-dn.net/?f=%5BZn%5E%7B2%2B%7D%5D%20%3D%20%201.6%20%5C%20M)
and ![[Zn^{2+}] = 2.00*10^{-2} \ M](https://tex.z-dn.net/?f=%5BZn%5E%7B2%2B%7D%5D%20%3D%20%202.00%2A10%5E%7B-2%7D%20%5C%20%20M)
respectively.
What is the cell emf for the concentrations given? Express your answer using two significant figures
Answer:
The value is 
Explanation:
Generally from the question we are told that
The concentration of ![[Zn^{2+}]](https://tex.z-dn.net/?f=%5BZn%5E%7B2%2B%7D%5D)
at the cathode is ![[Zn^{2+}]_a = 1.6 \ M](https://tex.z-dn.net/?f=%5BZn%5E%7B2%2B%7D%5D_a%20%3D%20%201.6%20%5C%20M)
The concentration of at the anode is ![[Zn^{2+}]_c = 2.00*10^{-2} \ M](https://tex.z-dn.net/?f=%5BZn%5E%7B2%2B%7D%5D_c%20%3D%20%202.00%2A10%5E%7B-2%7D%20%5C%20%20M)
Generally the the cell emf for the concentration is mathematically represented as
![E = E^o - \frac{0.0591}{2} log\frac{[Zn^{2+}]a}{ [Zn^{2+}]c}](https://tex.z-dn.net/?f=E%20%3D%20%20E%5Eo%20-%20%5Cfrac%7B0.0591%7D%7B2%7D%20log%5Cfrac%7B%5BZn%5E%7B2%2B%7D%5Da%7D%7B%20%5BZn%5E%7B2%2B%7D%5Dc%7D)
Generally the 
is the standard emf of a cell, the value is 0 V
So
![E = 0 - \frac{0.0591}{2} * log[\frac{ 2.00*10^{-2}}{1.6} ]](https://tex.z-dn.net/?f=E%20%3D%20%200%20%20-%20%20%5Cfrac%7B0.0591%7D%7B2%7D%20%20%2A%20log%5B%5Cfrac%7B%202.00%2A10%5E%7B-2%7D%7D%7B1.6%7D%20%5D)
=>
Answer:
The Speed of the vehicles is 9.34m/s
Explanation:
For an elastic collision the two bodies move with similar velocities after collision
Given
M1=1330kg
V1=15m/s
M2=805kg
V2=0(the car is parked on neutral)
The formula is
M1V1+M2V2=(M1+M2)V
1330*15+805*0=(1330+805)V
19950+0=2135V
2135V=19950
divide both sides by 2135
V=19950/2135
V=9.34m/s
Wind power is produced from the
wind turbines or sails that uses air flow to convert it into mechanical power.
It is an alternative to fossil fuel burning, it is all around, renewable,
clean, produces no greenhouse gases and uses little land. The advantages of
wind power have been greatly praised by many. However, it has disadvantages.
Wind power especially at farm is noisy and may spoil the view for their
neighboring people. Also the amount of electricity depends on the strength of
the wind. If no wind is around, no electricity is produced.
