Answer:
The initial speed of the ball is 30 m/s.
Explanation:
It can be assumed that the ball is thrown at an angle of 45 degrees to the ground. The ball lands 90 m away. We need to find the initial speed of the ball. We know that the horizontal distance covered by the projectile is called its range. It is given by :

u is the initial speed of the ball.


v = 29.69 m/s
or
v = 30 m/s
So, the initial speed of the ball is 30 m/s. Hence, this is the required solution.
De Broglie's identity gives the relationship between the momentum and the wavelength of a particle:

where
p is the particle momentum
m is its mass
v its velocity
h is the Planck constant

is the wavelength
By re-arranging the equation, we get

and by using the data about the proton, given in the text, we can find the proton's wavelength:
The answer is A. locations by the ocean typically do not get as cold in the winter or as hot in the summer as locations that are located inland.
Answer:
η = 0.882 = 88.2 %
Explanation:
The efficiency of the pulley system can be given as follows:

where,
η = efficiency of pulley system = ?
W_out = Output Work = (600 N)(0.6 m) = 360 J
W_in = Input Work = (35.7 N)(11.43 m) = 408.051 J
Therefore,

<u>η = 0.882 = 88.2 %</u>