(a) The force exerted by the electric field on the plastic sphere is equal to

where

is the charge of the sphere and E is the strength of the electric field. This force should balance the weight of the sphere:

where m is the mass of the sphere and g is the gravitational acceleration.
Since the two forces must be equal, we have:

and so we find the intensity of the electric field

(b) Now let's find the direction of the field. The electric force must balance the weight of the sphere, which is directed downward, so the electric force should be directed upward. Since the charge is negative, the force is opposite to the electric field direction, and so the direction of the electric field is downward.
The speed and distances are directly proportional. Use ratios to solve for vertical y-distance. The ratio of x-distance west to y-distance north equals the x-velocity to y-velocity.
x/y = vx/vy
41/y = 8.6/5.2
41/y = 1.65
41/1.65 = y
24.8 m = y
Answer: C
14.75g
Explanation:
Given that the half life time = 60.5s
Let No = initial mass = 59g
N = decayed mass
At time t = 0, No = 59g
At time t = 60.5s,
N = No/2 = 59/2
= 29.5g
At time t = 121
N = 29.5/2 = 14.75g
Therefore N = 14.75g
Answer:
B. silicate rocks and metals
Answer:
No.
Explanation:
Acceleration of an object is defined as the rate of change of velocity per unit time. It can be given by :
a = dv/dt
dv is the change in velocity i.e. final velocity-initial velocity
dt is change in time
At a particular time, its change in velocity can be one only. It would imply that a body cannot have two acceleration at a particular time.