We will find the mass from
mass = density x volume
We are told the density and must find the volume from the dimensions given
the volume of the washer will be the area x thickness (remembering to convert all measurements to meters)
if the washer had no hole, its area would be pi (0.0225m)^2 (remember to convert to meters and to use radius)
the area of the hole is pi(0.00625m)^2
so the area of the washer is pi[(0.0225m)^2 - (0.00625m)^2] = 1.5x10^-3 m
the volume of the washer is 1.5x10^-3 m x 1.5x10^-3 m = 2.25x10^-6 m^3 (the thickness of the washer is 1.5 mm = 1.5x10^-3m)
thus, the mass of the washer = 8598kg/m^3 x 2.25x10^-6m^3 = 0.0189kg = 18.9 grams

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3 years ago

A tennis player serves a tennis ball such that it is moving horizontally when it leaves the racquet. When the ball travels a hor

finlep [7]

Answer:

The initial velocity is 38.46 m/s.

Explanation:

The horizontal distance travel by the tennis ball = 13 m

The height at which the tennis ball dropped = 56 cm

Now calculate the initial speed of tennis ball.

The vertical velocity is zero.

Below is the calculation. Here, first convert centimetre into kilometre. So, height at which ball dropped is 0.56 km.