Mechanics | Relativity Answers

the ceiling of an arena is 45m above the floor. what is the minimum speed that a thrown ball would need to just reach the ceiling

A rock is dropped into a deep well and is heard to hit the ground 2.78 seconds after being dropped. Determine the depth of the well.

A train running along a straight track at 30m/s is slowex unformly to a stop in 44s. Find the acceleration and the stopping distance

Two forces act on the same object: F1 = 51.2 N at 52.1o and F2 = 80.1 N at 132o. Find the magnitude of the resultant force, in N.

A home run is hit in such a way that the baseball just clears a wall 20.0 m high, located 136 m from home plate. The ball is hit at an angle of 37.0° to the horizontal, and air resistance is negligible. (Assume that the ball is hit at a height of 1.0 m above the ground.)

A ball having a mass of 0.60 kg is attached to the end of a cord 1.2m long. The ball is swung horizontally in a circular path with a speed of 6.0m/s. What is the force in Newton’s which the string exerts on the ball?

A horizontal pipe of diameter 1.09 m has a
smooth constriction to a section of diameter
0.654 m . The density of oil flowing in the pipe
is 821 kg/m3.
If the pressure in the pipe is 7190 N/m2
and in the constricted section is 5392.5 N/m2,
what is the rate at which oil is flowing?
Answer in units of m3/s.
Don't round answer

A jet of water squirts out horizontally from a
hole on the side of the tank as shown below.
If the hole has a diameter of 3.75 mm , what
is the height of the water above the hole in
the tank?
Answer in units of cm.

A fireman standing on an 11 m high ladder
operates a water hose with a round nozzle of
diameter 2.1 inch. The lower end of the hose
(11 m below the nozzle) is connected to the
pump outlet of diameter 4.1 inch. The gauge
pressure of the water at the pump is
P(gauge)pump = P(abs)pump − Patm= 55 PSI = 379.212 kPa
Calculate the speed of the water jet emerging from the nozzle. Assume that water is an
incompressible liquid of density 1000 kg/m3
and negligible viscosity. The acceleration of
gravity is 9.8 m/s2. Answer in units of m/s.

A beaker of mass 1.1 kg containing 3.2 kg of
water rests on a scale. A 2.1 kg block of a
metallic alloy of density 5200 kg/m3
is suspended from a spring scale and is submerged
in the water of density 1000 kg/m3 as shown in the figure.
What does the hanging scale read? The
acceleration of gravity is 9.8 m/s2. Answer in units of N.

2.What does the lower scale read?
Answer in units of N.