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.
Answer:
The time taken is 1.76 s.
Explanation:
mass of student, m = 45 kg
height, h = 6 m
power, P = 1500 W
Power is defined as the rate of doing work.
Work done in moving height is
W = m g h
Let the time is t.
P = m g h / t
1500 = 45 x 9.8 x 6 / t
t = 1.76 s
Equal the tension of the line to the force needed to stop (deselerate) the mass from a speed of 9.2 ft/s to 0 in 4.4 inches.
Start converting all the information to the SI.
mass, m = 19 lb * [1kg/2.2046lb] = 8.618 kg
speed: 9.2 ft/s * .3048m/ft = .2.80 m/s
distance to stop: 4.4 in * [2.54cm/in]*[1m/100cm] = 0.11176 m
constant acceleration => Vf^2 = Vo^2 - 2ad
Vf = 0 => a= V0^2 / 2d = [2.80m/s]^2 / (2*0.11176m) = 35.1 m/s^2
Use the second Law of Newton
Net force = m*a = 8.618 kg * 35.1 m/s^2 = 302.5 N
Answer: 302.5 N
Heat increase causing global warming causing high sea levels
Answer:
1200000J
Explanation:
Kinetic energy = 1/2 x mass x velocity^2
From the question,
mass =60.0g
Veblcity =200m/s
Therefore
Kinetic energy = 1/2 x 60 x 200^2
1/2 x 60 x 200x200
1/2 x 60 x 40000
30 x 40000
1200000J