I believe it’s C. Plane .
<h3><u>Answer</u> :</h3>
Initial velocity = zero (i.e., free fall)
Final velocity = 30m/s
Acceleration due to gravity = 10m/s²
For a body falling freely under the action of gravity, g is taken positive
◈ <u>First equation of kinenatics</u> :
⇒ v = u + gt
⇒ 30 = 0 + 10t
⇒ t = 30/10
⇒ <u>t = 3s</u>
Hence, object will attain a speed of 30m/s after 3s.
Answer:
<u>Charge</u><u> </u><u>of</u><u> </u><u>the</u><u> </u><u>particle</u><u> </u><u>is</u><u> </u><u>1</u><u> </u><u>coulomb</u><u>.</u>
Explanation:
Force, F:

F is magnetic force.
B is the magnetic flux density.
e is the charge of the particle.
V is the velocity

Answer:
28.6 ohm
Explanation:
there is a 3rd resistor in series. voltage drop across the resistors will be equal to 60v
7*.2+7*.2 +.2x = 60
2.8+.2x = 60
.2x = 57.2
x = 28.6
Answer:
C. Surface area
Explanation:
The rate of chemical reaction depends on various factors such as:
- concentration and pressure
- nature of reactants
- temperature
- surface area
- presence of catalyst, etc.
Effect of surface area of reactants: the rate of a chemical reaction can be increased by increasing the the area of contact of the reacting substances. This is especially important when one or more of the reactants are solids., because only the particles of the solid that are exposed are able to take part in the reaction at each instant of time. Therefore, the greater the surface area of the solid reactant particles the faster the reaction.
The surface area of solid reactants can be increased by grinding or pelletizing, thus allowing for a greater contact between the reacting particles,
The instance in which one of the solid reactants was treated in a coffee grinder before adding to the reaction container is one way of increasing the surface area of a reactant.