Answer:
8.85m/s
Explanation:
The potential energy the watermelon held before dropping is Ep=mgh=2*9.8*4=78.4J.
When it strikes the ground, all of its Ep will transfer into Ek, so 1/2*m*v^2=78.4.
We already knew that m=2, so insert that in, we will get the V^2=78.4 m/s, V=8.85 m/s
Answer:
The force of friction.
Explanation:
Gravity keeps the car on the ground.
Motion Allows the car to move.
The force of speed doesnt make sense.
Friction would cause the car to stop moving.
Answer:
8.60 g/cm³
Explanation:
In the lattice structure of iron, there are two atoms per unit cell. So:
where
an and A is the atomic mass of iron.
Therefore:

This implies that:

= 
Assuming that there is no phase change gives:

= 8.60 g/m³
Answer:
<h2>Magnitude of the second charge is

</h2>
Explanation:
According to columbs law;
F = 
F is the attractive or repulsive force between the charges = 12N
q1 and q2 are the charges
let q1 = - 8.0 x 10^-6 C
q2=?
r is the distance between the charges = 0.050m
k is the coulumbs constant =9*10⁹ kg⋅m³⋅s⁻⁴⋅A⁻²
On substituting the given values
12 = 9*10⁹*( - 8.0 x 10^-6)q2/0.050²
Cross multiplying
