The total energy or mechanical energy is the sum of the potential energy plus the kinetic energy, as it is known the velocity and the height, we can determine the total energy.

$E_{M}=E_{p} + E_{k} \\E_{p} = potential energy [J]\\E_{k} = kinetic energy [J]\\where:\\E_{p} =m*g*h\\E_{p} = 4*9.81*0.5=19.62[J]\\E_{k}=\frac{1}{2} *m*v^{2} \\E_{k}=\frac{1}{2} *4*(3)^{2} \\E_{k}=18[J]\\Therefore\\E_{M} =18+19.62\\E_{M}=37.62[J]$

All this energy will become kinetic energy and we can find the velocity.

$37.62=\frac{1}{2} *m*v^{2} \\v=\sqrt{\frac{37.62*2}{4} } \\v=4.33[m/s]$

8 0

3 years ago

If the soccer ball has a mass of 284g, and gravitational force is 9.81 m/s2 on Earth, what is the weight of the soccer ball?

bagirrra123 [75]

Answer:

2.79 N
8.34 N
Watermelon

Explanation:

Weight of soccer ball

Weight = mass (in kg) × gravitational force
Weight = 284 x 10⁻³ x 9.81
Weight = 0.284 x 9.81
Weight = 2.79 N (approximately)

Weight of watermelon

Weight = mass (in kg) x gravitational force
Weight = 850 x 10⁻³ x 9.81
Weight = 0.85 x 9.81
Weight = 8.34 N (approximately)

As the watermelon has more weight, it will hit the ground first.

4 0

2 years ago