Answer:
Explanation:
Yes she is doing work. With or without the groceries, she is still doing work. She does more work with the groceries than without because Work is defined by F which is defined by mass. The mass increases with the groceries.
The work done is against the force of gravity.
Answer: tensional force
Explanation:
Tension force on a material occurs when two equal forces act on a material in an opposite direction away from the ends of the material.
Pre-tensing a wire material increases its load bearing capacity and reduces its flexure.
Answer:
Explanation: heat of fusion
Answer:
Area of the rectangular field in kilometers is 0.09 
Explanation:
We know that 1 kilometers = 1000 meters
since we need to find the area in unit of kilometers
therefore converting length and width into kilometers
1000 meters = 1 kilometers
300 meters =
Likewise width = 0.3 km
Area = length x width
= 0.3km x 0.3 km
= 0.09 
Answer:
r = 0.22m
Explanation:
To find the radius of the circular trajectory, you first take into account that the centripetal force of the charged particle, is equal to the electric force between the particle that is moving and the particle at the center of the orbit.
Then, you have:
(1)
m: mass of the particle = 20g = 20*10-3 kg
ac: centripetal acceleration = ?
q: charge of the particle = 5*10^-6C
Fe: electric force between the charges
The electric force is given by:
(2)
r: radius of the orbit
q': charge of the particle at the center of the orbit = -5*10^-6C
Furthermore, the centripetal acceleration is:
(3)
v: speed of the particle = 7m/s
You replace the expressions (2) and (3) in the equation (1) and solve for r:

Finally, you replace the values of all parameters in the previous expression:

The radius of the circular trajectory is 0.22m