Answer:
714.285s
Explanation:
use relative velocity
8-4.5 = 3.5m/s
x = 2500m
2500/3.5 = 714.285s = 700s (with sig figs)
Answer:
nope don't think so
Explanation:
the heat causes the molecules to move faster therefore expanding in watever it the air is in
Answer:
gravitational force
electrostatic force
Explanation:
The forces that balloons may exert on each other can be gravitational pull due to the mass of the balloon membrane and the mass of the gas contained in each. This force is inversely proportional to the square of the radial distance between their center of masses.
The Mutual force of gravitational pull that they exert on each other can be given as:

where:
gravitational constant 
are the masses of individual balloons
the radial distance between the center of masses of the balloons.
But when there are charges on the balloons, the electrostatic force comes into act which is governed by Coulomb's law.
Given as:

where:

are the charges on the individual balloons
R = radial distance between the charges.
Answer: 2812500 joules
Explanation:
Mass of car = 1500kg
Velocity of car = 75mph
Kinetic energy = ?
Recall that kinetic energy is the energy possessed by a moving object, and it depends on its mass M and velocity, V
Thus, Kinetic energy = 1/2 x mv^2
= 1/2 x 1000kg x (75mph)^2
= 0.5 x 1000kg x (75mph)^2
= 500 x 5625
= 2812500 joules
Thus, the car travels with a kinetic energy of 2812500 joules
The 48 and 47 are different atomic masses, this is caused by having a different number of neutrons.