Answer:
<em>The second ball has four times as much kinetic energy as the first ball.</em>
Explanation:
<u>Kinetic Energy
</u>
Is the type of energy an object has due to its state of motion. It's proportional to the square of the speed.
The equation for the kinetic energy is:
Where:
m = mass of the object
v = speed at which the object moves
The kinetic energy is expressed in Joules (J)
Two tennis balls have the same mass m and are served at speeds v1=30 m/s and v2=60 m/s.
The kinetic energy of the first ball is:
The kinetic energy of the second ball is:
Being m the same for both balls, the second ball has more kinetic energy than the first ball.
To find out how much, we find the ratio:
Simplifying:
The second ball has four times as much kinetic energy as the first ball.
The right answer is c. You are going to divide by the velocity or speed by time.
Complete question:
Point charges q1=- 4.10nC and q2=+ 4.10nC are separated by a distance of 3.60mm , forming an electric dipole. The charges are in a uniform electric field whose direction makes an angle 36.8 ∘ with the line connecting the charges. What is the magnitude of this field if the torque exerted on the dipole has magnitude 7.30×10−9 N⋅m ? Express your answer in newtons per coulomb to three significant figures.
Answer:
The magnitude of this field is 826 N/C
Explanation:
Given;
The torque exerted on the dipole, T = 7.3 x 10⁻⁹ N.m
PEsinθ = T
where;
E is the magnitude of the electric field
P is the dipole moment
First, we determine the magnitude dipole moment;
Magnitude of dipole moment = q*r
P = 4.1 x 10⁻⁹ x 3.6 x 10⁻³ = 1.476 x 10⁻¹¹ C.m
Finally, we determine the magnitude of this field;
E = 826 N/C (in three significant figures)
Therefore, the magnitude of this field is 826 N/C
