Answer:
B
Explanation:
Given that an elevator moving down passes its neighbor, an elevator moving up. Their speed relative to one another is 8 m/s. What is the velocity of each elevator relative to someone standing on the first floor? Assume that the elevators are traveling at the same speed, and that the upward direction is
positive.
Solution
Given that upward direction is positive, then, the downward direction will be negative.
To get a relative velocity of 8m/s
4 - ( - 4 ) = 8
Therefore, the correct answer will be
One elevator is moving at 4 m/s; the other elevator is moving at -4 m/s
Which is option B
Because the negative multiply by negative sign will give positive sign.
Given
4 + 4 = 8.
Explanation:
Solids have a definite shape and definite volume.
Answer:
The electric field intensity is <u>30000 N/C.</u>
Explanation:
Given:
Magnitude of the point charge is, 
Distance of the given point from the point charge is, 
Electric field intensity is directly proportional to the magnitude of point charge and inversely proportional to the square of the distance of the point and the given charge.
Therefore, electric field intensity 'E' at a distance of 'd' from a point charge 'q' is given as:
Plug in 
. Solve for 'E'.
Therefore, the electric field intensity at a point 3 cm from the point charge is 30000 N/C.
Centripetal force = (mass) x (speed)² / (radius)
= (20 kg) x (20 m/s)² / (20 m)
= (20 x 20 / 20) (kg-meter/sec²)
= 20 newtons
To add vectors we can use the head to tail method (Figure 1).
Place the tail of one vector at the tip of the other vector.
Draw an arrow from the tail of the first vector to the tip of the second vector. This new vector is the sum of the first two vectors.
