All the spheres are similar because they have no edges
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.
Complete question:
It is measured that 3/4 of a body's volume is submerged in oil of density 800kg/m³. What is the specific gravity of oil?
Answer:
The specific gravity of the oil is 0.8.
Explanation:
Given;
density of the oil,
= 800 kg/m³
density of water,
= 1000 kg/m³
The specific gravity of any substance is the ratio of the substance density to the density of water.
Specific gravity of the oil = density of the oil / density of water
Specific gravity of the oil = 800/1000
Specific gravity of the oil = 0.8
Therefore, the specific gravity of the oil is 0.8.
Answer:
more time to change the momentum of falling rocks
Explanation:
Momentum is related to "mass in motion." So, if an object is moving, then it has momentum as it has its mass in motion. The amount of momentum is dependent upon how much and how fast the object is moving.
If an object is moving slowly, it means that the object is losing momentum.
Nets used to catch falling boulders on the side of rocky hillside roadways are more effective than rigid fences because their breakage is reduced by more time to change the momentum of falling rocks.
Answer:
The amount of matter in an object is its mass
An action that has the ability to change an object's state of motion is a force
The rate at which velocity changes over time is acceleration
Explanation:
- Mass is a scalar quantity that gives a measure of the amount of matter contained in an object/substance. The SI unit of the mass is the kilogram (kg). Mass is an intrinsec property of an object, that means that it does not change when the object is moved in another location.
- A force is a vector quantity, that indicates an action exerted on an object that changes the state of motion of the object. It is measured in Newtons (N). According to Newton's second law, the acceleration of an object is equal to the net force exerted on the object divided by its mass:

- Acceleration is a vector quantity, which is equal to the ratio between the change in velocity of an object and the time interval taken for that change to occur. It is measured in meters per second squared (
). Mathematically, it is defined as
