Answer:
6.0 m/s
Explanation:
According to the law of conservation of energy, the total mechanical energy (potential, PE, + kinetic, KE) of the athlete must be conserved.
Therefore, we can write:

or

where:
m is the mass of the athlete
u is the initial speed of the athlete (at the bottom)
0 is the initial potential energy of the athlete (at the bottom)
v = 0.80 m/s is the final speed of the athlete (at the top)
is the acceleration due to gravity
h = 1.80 m is the final height of the athlete (at the top)
Solving the equation for u, we find the initial speed at which the athlete must jump:

Frequency and speed = wavelength.
Answer:
Short answer, because copper wire does not have high resistance.
Explanation:
30 Grams would be your answer (I took the test and got it right)
Answer:
Because it has more mass
Explanation:
To understand this, think about the equation of kinetic energy
KE =
m 
Kinetic energy depends on both the velocity (v) as well as the mass (m).
Because a lorry is bigger and heavier than a car, it will have more mass. With more mass, at the same velocity the lorry with have more kinetic energy.