<span>We know that an object in moving with acceleration follow the rule according that
the distance covered will be : d = Vi*t + 1/2*a*t^2
where d is distance, Vi is initial speed, and a is acceleration
Then after 1 km which is 1000 metres we have:
1000 = Vi *71.2 + 1/2*0.0499*(71.2)^2
Vi = (1000-1/2*0.0499*(71.2)^2)/71.2 = 1000/71.2 - 1/2*0.0499*71.2 = 12.27 m/s
Then the car was going at 12.27 m/s when started to accelerate.</span>
Answer:
a) F = 2.25 10³ N, b) REPULSIVE.
Explanation:
a) The electric force is given by coulomb's law
F = 
k q1q2 / r2
in this case nso indicate that the two charges have the same value
q₁ = q₂ = 2.5 10⁻⁶ C
Let's reduce the magnitudes to the SI system
r = 0.5 cm (1m / 100cm) = 5 10⁻³ m
let's calculate
F = 
F = 2.25 10³ N
b) In electricity, electric charges of the same sign repel and those of the opposite sign attract
In this exercise, the balls are equal and are rubbed with the same material, for which it acquires charges of the same type, consequently, as the charges are of the same type, they indicate that the negative force is REPULSIVE.
When temperature increases, particles in an object speed up, which means an increase in thermal energy<span>. Since the particles are moving more now, the potential energy decreases, therefore kinetic energy increases. Overall,when temperature go up, thermal energy go up, which leads to an increase to kinetic energy.</span>
Martha studies all the kinds of leaves she can find in order to understand what leaves have in common . Martha's research is employing B. INDUCTIVE reasoning.
