When you touch<span> a doorknob (or something else made of metal), which has a positive charge with few electrons.</span>
Average speed = total distance / total time
total distance = 40 + 20 = 60km
total time taken = 10 + 5 = 15 minutes
Average speed = 60/15 = 4km/min
Answer:
C. Burning coal tends to harm the environment more than using solar panels.
Explanation:
When coal is burned, it reacts with the oxygen in the air. This reaction converts the stored potential energy, which turns into thermal energy, which is released as heat. But it also produces methane and carbon dioxide which is released into the air.
Answer is B- 200 m
Given:
m (mass of the car) = 2000 Kg
F = -2000 N
u(initial velocity)= 20 m/s.
v(final velocity)= 0.
Now we know that
<u>F= ma</u>
Where F is the force exerted on the object
m is the mass of the object
a is the acceleration of the object
Substituting the given values
-2000 = 2000 × a
a = -1 m/s∧2
Consider the equation
<u>v=u +at</u>
where v is the initial velocity
u is the initial velocity
a is the acceleration
t is the time
0= 20 -t
t=20 secs
s = ut +1/2(at∧2)
where s is the displacement of the object
u is the initial velocity
t is the time
v is the final velocity
a is the acceleration
s= 20 ×20 +(-1×20×20)/2
<u>s= 200 m</u>
I think that number five is lithium
