Answer:
42m/s
6.06s
Explanation:
To find the initial velocity and time in which the ball is fling over the ground you use the following formulas:

θ: angle = 45°
vo: initial velocity
g: gravitational constant = 9.8m/s^2
x_max: max distance = 180 m
t_max: max time
by replacing the values of the parameters and do vo the subject of the first formula you obtain:

with this value of vo you calculate the max time:

hence, the initial velocity of the ball is 42m/s and the time in which the ball is in the air is 6.06s
- - - - - - - - - - - - -- - - - - - - - - - - - - -
TRANSLATION:
Para encontrar la velocidad inicial y el tiempo en el que la pelota está volando sobre el suelo, use las siguientes fórmulas:
θ: ángulo = 45 °
vo: velocidad inicial
g: constante gravitacional = 9.8m / s ^ 2
x_max: distancia máxima = 180 m
t_max: tiempo máximo
reemplazando los valores de los parámetros y haciendo el tema de la primera fórmula que obtiene:
con este valor de vo usted calcula el tiempo máximo:
por lo tanto, la velocidad inicial de la pelota es de 42 m / sy el tiempo en que la pelota está en el aire es de 6.06 s
Answer:
B. 59 kg
Explanation:
From the graph you notice that a linear relation in indicated by the line joining the points such that the points on the line represent the data that show a correct relationship in the experiment.
This means that the point outside the line has an error .
This point is the value 59 kg that does not align with other values which are included in the graph.
Answer:
4.71 eV
Explanation:
For an electromagnetic wave with wavelength

the energy of the photons in the wave is given by

where h is the Planck constant and c the speed of light. Therefore, this is the minimum energy that a photon should have in order to extract a photoelectron from the copper surface.
The work function of a metal is the minimum energy required by the incident light in order to extract photoelectrons from the metal's surface. Therefore, the work function corresponds to the energy we found previously. By converting it into electronvolts, we find:

Answer:
The force acting on a body is always equal to the product of the mass of the body and its acceleration.
Explanation:
The force of a body is defined as the product of mass and acceleration of the body.
According to Newton's second law, wherever there is a change in momentum of the body for an interval of time, there is a force acting on it.
F = (mv - mu) / t
= m (v -u) /t
= m a
Where,
(v - u)/t - is the change in velocity of the body in the interval of time. It is equal to the acceleration of the body.
Hence, the equation for the force for any body becomes, F = m x a