Answer:
Their experimental design lacks control group
Explanation:
Based on what I read, the scientists don't have a control group as one of the main groups thus they cannot, in scientific sense, say that the medicine is better or worse. You always need a control group receiving no intervention because then we can compare groups and assess the effectiveness of that intervention (in our case if we had control group vs people who received the medicine, we could see if the people who received the medicine had improved condition etc when compared to participants who did not receive anything)
Force applied on the car due to engine is given as
towards right
Also there is a force on the car towards left due to air drag
towards left
now the net force on the car will be given as

now we can say that since the two forces are here opposite in direction so here the vector sum of two forces will be the algebraic difference of the two forces.
So we can say



So here net force on the car will be 150 N towards right and hence it will accelerate due to same force.
Angle α between the velocity of theelectron and the magnetic field of the wire will be 90 degree
Answer:
The time taken by the projectile to hit the ground is 6.85 sec.
Explanation:
Given that,
Vertical height of cliff = 230 m
Distance = 300 m
Suppose, determine the time taken by the projectile to hit the ground.
We need to calculate the time
Using second equation of motion

Where, s = vertical height of cliff
u = initial vertical velocity
g = acceleration due to gravity
Put the value in the equation



Hence, The time taken by the projectile to hit the ground is 6.85 sec.
Answer:
Quantity of charge = 80 Coulombs
Explanation:
Given the following data;
Current = 2 A
Time = 40 seconds
To find the amount of charge flowing through the light bulb;
Mathematically, the quantity of charge passing through a conductor is given by the formula;
Quantity of charge = current * time
Substituting into the formula, we have;
Quantity of charge = 2 * 40
Quantity of charge = 80 Coulombs