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.
Wood i think could be wrong
by the concept of momentum conservation we can say
if net force on a system of mass is ZERO then its momentum will remain conserved
Here a ball is projected upwards so if we take Ball + Earth as a system then total momentum of the system will remain conserved
Initially when ball is on the surface of earth the system has zero momentum and hence we can say after throwing the ball momentum of earth + ball must be zero
now using same equation we can say
given that
from above equation velocity of earth will be
so above will be the recoil speed of earth
It believe it is under the ground because it normally is in tunnels
Answer:
1.275 m
Explanation:
Let the maximum height reached be h.
Here initial velocity, u = 5 m/s
Final velocity, V = 0
Use third equation of motion
V^2 = u^2 + 2 g h
0 = 25 - 2 × 9.8 × h
h = 25/19.6 = 1.275 m
