Answer:False
Explanation:
Work is being done on a body when it causes displacement of body on the application of force
When we pull the door by a force it causes zero displacements of the door. So we can say that work done on it is zero.
Thus the above-given statement is false
Answer:
Yes. Inertia keeps the speed maintained though my feet leave the ground.
Explanation:
Inertia is the resistance to the change in position of any object this means this resistance will keep me traveling at 30 km/s relative to the sun. If the person wants to change the position we apply force to do that because inertia is opposing us to not do that. We are always traveling with 30km/s relative to sun due to inertia.
Think its Positive
hope this helpes
Mass is the physical quantity
Answer:
hmax = 1/2 · v²/g
Explanation:
Hi there!
Due to the conservation of energy and since there is no dissipative force (like friction) all the kinetic energy (KE) of the ball has to be converted into gravitational potential energy (PE) when the ball comes to stop.
KE = PE
Where KE is the initial kinetic energy and PE is the final potential energy.
The kinetic energy of the ball is calculated as follows:
KE = 1/2 · m · v²
Where:
m = mass of the ball
v = velocity.
The potential energy is calculated as follows:
PE = m · g · h
Where:
m = mass of the ball.
g = acceleration due to gravity (known value: 9.81 m/s²).
h = height.
At the maximum height, the potential energy is equal to the initial kinetic energy because the energy is conserved, i.e, all the kinetic energy was converted into potential energy (there was no energy dissipation as heat because there was no friction). Then:
PE = KE
m · g · hmax = 1/2 · m · v²
Solving for hmax:
hmax = 1/2 · v² / g
