Answer: 3 m/s
Explanation:
The average velocity is simply the change in displacement over the specified time interval. I’m this case, we have a total of four intervals,which represent 4 seconds. Dividing 12 m by 4s gives us 3 m/s
Answer: when the ball moves to the east
Explanation:
Work is done when an external force makes an object move in the direction that it was forcing it to by transferring energy to it.
The wind is blowing to the east which means that it is exerting a force that is trying to move the ball to the east. For work to actually occur, the ball needs to move in the direction of the force being applied which is the east.
Answer:
The girl is doing work on the ball because the energy in her muscles changed, even though the ball is not displaced.
Explanation:
The complete question is...
Which of these correctly describes whether a girl holding a ball in the same position is doing work on the ball?
-The girl is doing work on the ball because the energy of the ball changed, even though it is not displaced.
-The girl is doing work on the ball because the energy in her muscles changed, even though the ball is not displaced.
-The girl is doing no work on the ball because the ball is not displaced.
-The girl is doing no work on the ball because she is exerting a net force on the ball.
Holding up a ball costs energy, which is used to counter the work that would have otherwise be done on the ball by gravity. Although no physical distance is moved, we should consider the fact that by holding the ball, the girls hand exerts physical force to hold the ball in place. Also, there is a potential gravitational work on the ball due to gravity, but the force exerted by the girls hand does an equivalent of this gravito-potential work in order to counter it and hold the ball in place. All these activities eventually lead to a change in energy in her hand muscle to show that energy is expended.
Answer:
Explanation:
350 cm / 25 cm = 14 radians
14 rad / 2π rad/rev = 2.23 revolutions
Answer:
1020.4kg/m³
35m³
Explanation:
Given parameters:
Depth = 0.5m
Pressure exerted = 5000N/m²
Unknown = density of the liquid = ?
Solution:
To find the density of this unknown liquid, we use the expression below:
Pressure of liquid = density x height x acceleration due to gravity
5000 = density x 0.5 x 9.8
Density = 1020.4kg/m³
B.
Density of water = 1000kg/m³
Mass of water = 35000kg
Unknown:
Volume of water = ?
Solution:
The volume of water can be derived from the expression below:
Volume =
Volume = = 35m³