Answer:
679.2 m/s
Explanation:
The formula for the time of flight of a projectile is given as,
T = 2usinФ/g ......................... Equation 1
Where T = Time of flight, u = initial velocity, Ф = angle of projectile to the horizontal, g = acceleration due to gravity.
make u the subject of the equation
u = Tg/2sinФ....................... Equation 2
Given: T = 69 s, Ф = 30°
Constant: g = 9.8 m/s²
Substitute into equation 2
u = (69×9.8)/(2×sin30)
u = 679.2 m/s.
Hence the initial speed of the projectile is 679.2 m/s
Answer:
B. If the container is cooled, the gas particles will lose kinetic energy and temperature will decrease.
C. If the gas particles move more quickly, they will collide more frequently with the walls of the container and pressure will increase.
E. If the gas particles move more quickly, they will collide with the walls of the container more often and with more force, and pressure will increase.
#FreeMelvin
Answer:
Explanation:
Capacitance is defined as the charge divided in voltage.
Introducing a dielectric into a parallel plate capacitor decreases its electric field. Therefore, the voltage decreases, as follows:
Where k is the dielectric constant and 
the voltage of the capacitor without a dielectric
The capacitance with a dielectric between the capacitor plates is given by:
Where k is the dielectric constant and 
the capacitance of the capacitor without a dielectric. So, we have:
Therefore, a capacitor with a dielectric stores the same charge as one without a dielectric.
1.21 (this needs twenty so i have to write so yeah deal with it)
