Answer: 4
The mechanical advantage is the ratio of the force exerted by the object to the force applied to do work on it.
Here, Jeff tried to lift a rock weighing 600 pounds by wedging board under the rock. Jeff who weighs 150 pounds uses all his weight to exert force on lever and lift rock.
Mechanical advantage, 
Therefore, the mechanical advantage that lever provided to Jeff in lifting rock is 4.
Answer: Option (B)
Explanation: A stream transports its materials in different ways-
- <u>Dissolved load-</u> Here, the materials gets dissolved when mixed with water and flows along with the stream.
- <u>Suspended load</u>- Here, the materials are not fully dissolved in the water but they can be carried from one place to another in suspension mode, by the river.
- <u>Bed load-</u> Bed load are transported in three different ways such as-
- Sliding- here, the materials slides down along a curved surface under the water and carried away.
- Rolling- here, the materials are solid and due to force exerted by water, it can roll and move to distant places.
- Saltation- here, the materials are carried away in a series of jumps.
Thus, the most appropriate answer is option (B) i.e bedload.
Answer:
No.
Explanation:
The only way a twist may be done is if the trans form of an alkene/alkyne is twisted into the cis form--only if/when the pi bond is brokwn.
Answer: When the electric field due to one is a maximum, the electric field due to the other is also a maximum, and this relation is maintained as time passes. They alternatively reinforce and cancel each other.
Explanation:
In a wave, the phase, is an arbitrary time reference, used to locate a given point of the wave in time, within a cycle.
Two waves can travel at the same speed, or even have the same wavelength, but this is not enough to be sure that at a given point in time, both waves will be in their maximum, as it only can be determined from the phase of the waves.
So, only when the waves reach at the same point in time at the same amplitude, we can say that they arrive in phase, in a constructive interference.
Answer:
Charge, 
Explanation:
It is given that,
The number of electron in a RBCs, 
We need to find the total charge of these electrons in the red blood cell. Let it is q. Using the quantization of charge as follows :
q = ne
e is the change on electron
So, the net charge is 
.
