Answer:
B.) a wheel and axle and a lever
Explanation:
P.S - The exact question is -
Given - A wheelbarrow can be used to help lift a load, such as a pile of dirt, and then push the load across a distance. A man pushes a wheelbarrow.
To find - Which simple machines make up a wheelbarrow?
A.) a pulley and an inclined plane
B.) a wheel and axle and a lever
C.) a pulley and a wheel and axle
D.) a lever and a wedge
Proof -
The correct option is - B.) a wheel and axle and a lever
Wheelbarrows are used to carry more goods from place to place by using minimal force as compared when goods are carried by hand.
With this machine, During hauling people can save time.
Answer:
As evolutionary biologists have shown, this multicellularity was linked to the rise in oxygen and thus played a significant role for life on Earth as it is today. ... By producing oxygen and evolving into multicellular forms, they played a key role in the emergence of organisms that breathe oxygen.
Explanation:
Answer:
a) Current = 11 mA
b) Energy = 66 mJ
c) Power = 101.54 W
Explanation:
a) Voltage, V = IR
Voltage, V = 6 V, Resistance, R = 550 Ω
Current, I 
b) Energy = Current x Voltage = 6 x 0.011 = 0.066 J = 66 mJ
c) 
Protons are positive, electrons are negative, and neutrons are neutral. In the nucleus, there are protons and neutrons, so the charge of a nucleus is positive
The time of fall for the two balloons is equal.
Here the conditions given resembles a free fall. Since the air resistance is negligible, gravitational force is the only force acting on both the balloons which means the two balloons are falling in a vacuum. In a vacuum, if two objects of different mass are thrown from the same height, both objects will reach the ground at the same time.
Free fall is nothing but a condition in which an object falls solely under the influence of gravity.
Therefore, the time of fall for both yellow and red water balloons is equal no matter the weight where air resistance is negligible.
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