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.
Given:
Object in circular motion 25 m/s
1 second to go quarter circle
Required:
Centripetal acceleration:
Solution:
Acceleration = v2/r
Where v is the velocity and r is
the radian
Substituting the values into the
equation,
Acceleration = v2/r = (25
m/s)2/(4*pi/180) = 8952.47 m2/s2
If two people hit identical tennis balls at the same time, the ball that has the most kinetic energy is the ball that moves at the fastest speed.
<u>Explanation:</u>
The energy possessed by an object by virtue of its motion is called its kinetic energy indicating that only moving objects have kinetic energy. The kinetic energy of an object depends on its speed and mass.
It is given by the expression
where m denotes the mass of the object and v denotes its velocity.
since kinetic energy is directly proportional to the square of the velocity, the kinetic energy of an object increases with its velocity.
Hence an object that moves at the fastest speed will have the most kinetic energy.
