Answer:
The radius r of the metal sphere.
Explanation:
From Gauss's law we know that for a spherical charge distribution with charge 
, the electrical field at distance 
from the center of the sphere is given by
What is important to notice here is that the radius of the sphere does not matter because any test charge sitting at distance feels the force as if all the charge were sitting at the center of the sphere.
This situation is analogous to the gravitational field. When calculating gravitational force due to a body like the sun or the earth, we take not of only the mass of the sun and the distance from it's center; the sun's radius does not matter because we assume all of its mass to be concentrated at the center.
Answer:
Right shoe
Explanation:
Let the mass and velocity of incoming puck be m and v respectively.
Momentum of the colliding puck will be mv
In case of first case , the momentum of puck becomes zero so change in momentum after collision with left shoe
= mv - 0 = mv
If time duration of collision be t
rate of change of momentum
= mv / t
This is the force exerted by puck on the left shoe .
Now let us consider collision with right shoe
momentum after collision with right shoe
- mv
change in momentum
= mv - ( - mv ) = 2mv
If time duration of collision be t
rate of change of momentum
= 2mv / t
This is the force exerted by puck on the right shoe .
Since the force on the right shoe is more , this shoe will have greater speed
after collision.
Although one could definitely directly connect an "apple falling" with Newton's first law of motion, which is gravity, since the question states about acceleration, then we can relate the statement to Newton's second law of motion, the law of acceleration.
Answer:
the statement is TRUE
Explanation:
When we move in the same direction, the relative speed of the two vehicles is lower, so we must subtract their speeds, if the result is positive the vehicles approach and if it is negative they move away.
v_relative = v₁ - v₂
When the two vehicles go in opposite directions, the speed is much higher, so we must add their speeds
v_relative = v₁ - (-v₂))
v_relative = v₁ + v₂
therefore the statement is TRUE
