Answer:
Explanation:
Given
Each student exert a force of 
Let mass of car be m
there are 18 students who lifts the car
Total force by 18 students 
therefore weight of car 
mass of car 

(b)
Answer:
2) c) give-way vessel
3) a) With one short blast
Explanation:
2) A vessel that is required to take early substantial action to ensure avoiding collision called Give way vessel
In overtaking, the vessel intending to overtake is the Give-Way Vessel the vessel that is going to be overtaken is the Stand-On Vessel
Therefore, the correct option is c) give-way vessel
3) When vessels use sound signals in a meeting head on situation both vessel are Give-Way vessels and both vessel pass the each other by turning to the starboard side therefore they intend to pass each other on their port side requiring one short blast
Therefore, the correct option is a) With one short blast.
The strength of the electric field is 5 N/C
Explanation:
The magnitude of the electric field produced by a single-point charge is given by:

where
is the Coulomb's constant
Q is the magnitude of the charge
r is the distance from the charge
In this problem, we have:
is the charge producing the field
r = 100 m is the distance from the charge at which we want to calculate the field
Substituting into the equation, we find the s trength of the electric field:

Learn more about electric field:
brainly.com/question/8960054
brainly.com/question/4273177
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<span>The diameter of the Moon is 3,474 km. Now, let's compare this to the Earth. The diameter of the Earth is 12,742 km. This means that the Moon is approximately 27% the size of the Earth.</span>
Answer:
2. 200N
3.50kg
4.700N
Explanation:
Weight is another word for the force of gravity
Weight is a force that acts at all times on all objects near Earth.
F=m*g
where g=acceleration due to gravity
2. due to the gravitational fields of the earth , assume gravitational acceleration=10m/s2
F=20*10= 200N
3.same as above
mass=Force/gravitational acceleration
mass=500/10 = 50kg
4.force=mass*gravitational acceleration
force=70*10=700N