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Mechanics: Problems and Solutions

1. A projectile of mass 0.6 kg is fired vertically upwards in the barrel of a gun by a vertical net propelling force of 50 N acting over a period of 0.5 seconds. Calculate: (a) The velocity of the projectile when it leaves the gun. (b) The height reached by the projectile. (c) The time taken from the projectile leavin

Stress in the bones of the arm during the swing

1. Find an equation for the terminal velocity of a sphere falling through a viscous fluid (like water or blood). How does the terminal velocity scale with the size of the falling object? Assume that the density of that object is much larger than that of the fluid through which it falls (neglect buoyancy). a. V ~ L^-3 b. V


1. A 4.5 kg block is at rest on a table when it is attached to a second mass, m2 hanging over a pulley. The static coefficient of friction between the block and the table is 0.56 and kinetic coefficient is 0.42, respectively. The hanging mass, m2 is chosen to be 2.4 kg. a) Will this choice for m2 set the system in motion? b)

Physics: Velocity, Magnitude and Direction

Hi, I need some assistance with the following questions: 1. A cannon ball is fired with a velocity of 48 m/s at 42 degrees up from the horizontal. Assume that it lands at the same level as it was fired from. a. Find the maximum height of the cannon ball. b. Find the total time the cannon ball is in the air. c. Find the

9 Physics Problems and Solutions

1. To qualify for the finals of a racing event, a race car must achieve an average speed of 220 km/h on a track with a total length of 2400 m. If a particular car covers the first 1000 m of the track with an average speed of 180 km/h, what minimum average speed must it have on the remainder of the track to qualify? 3. How lon

Frictional Force and Velocity of Water

A 150-lb fireman is holding a hose which has a nozzle diameter of 1 inch and hose diameter of 2 inches. If the velocity of the water at discharge is 60 ft/s - determine the resultant normal and frictional force acting on the man's feet at the ground. (Neglect the weight of the hose and the water within it. yw = 62.4 lb/ft3).

7 problems on rotational motion and two problems on density

1. Competitive divers pull their limbs in a curl up their bodies when they do flips. Just before entering the water, they fully extend their limbs to enter straight down. Explain the effect of both actions on their angular velocity. What is the effect of these actions on their angular momentum? 2. (A) Show that for a hoop of

Derivatives : Displacement, Velocity and Acceleration

A car brakes in an emergency, the moment the brakes are first applied is t=0. the car's distance, s, from the point at which the brakes were first applied is given by: S = -0.1t^3 + 20t + 0.1 (i) Differentiate s to find formulae for the velocity and acceleration. (ii) Find the time at which the car comes to a stop. (iii)

Force on Current Carrying Wires and Drift Velocity

Please see the attached file for the problem statement, and provide a fully worked-out solution. In order to get an idea of the magnitude of magnetic forces, find the force per unit length between very long equal and opposite 10 ampere currents separated by 1 centimeter. Find the ratio of this to the weight per unit length of

Electron drift velocity

Calculate the drift velocity of electrons in a copper wire given the current flowing in it, its diameter and density. A copper wire 2.5 millimeters in diameter is carrying a current of 10 amperes. Assume one free electron per copper atom and find the magnitude of the drift velocity. [Copper has a density of 8.92 grams/(cent

Fluids:Dam and Plug

A dam to create a large fresh water lake is constructed. It will be approximately 14 meters deep. A horizontal pipe 1.2 meters long and 4 cm in diameter will pass through the dam at a depth of 7 meters to allow for release of the water in emergencies and for sampling. In normal situations, a plug will secure the pipe opening.

Projectile motion: horizontal distances and vertical speeds

A rescue plane wants to drop supplies to isolated mountain climbers on a rocky ridge 235 m below. The plane is traveling horizontally with a speed of 240 km/h (66.7 m/s). (a) How far in advance of the recipients (horizontal distance) must the goods be dropped? (b) Suppose, instead, the plane releases the supplies a horiz

Ideal Ball Projectile Motion

A ball is thrown directly downward, with an initial speed of 8.50 m/s, from a height of 31.0 m. After what time interval does the ball strike the ground?

Toy Cars: Velocity, position, and acceleration

At t = 0, one toy car is set rolling on a straight track with initial position 13.0 cm, initial velocity -3.5 cm/s, and constant acceleration 2.50 cm/(s^2). At the same moment, another toy car is set rolling on an adjacent track with initial position 10.5 cm, an initial velocity of 6.10 cm/s, and constant zero acceleration. (a)

4 Problems: Vectors, Displacement and equations of motion.

Please see the attached file for full problem description. 1.) A basketball player runs down the court, following the path indicated by the vectors A, B, and C in Figure 3-38. The magnitudes of these three vectors are: A = 10.0 m, B = 21.0 m, and C = 7.0 m. Let the +x axis point to the right and the +y axis point to the far s

Physics - Pressure and Volume

1. Calculate the following. a. 100 ml of liquid A has a mass of 250 g. What is its density, in kg/L? (Note: 1 L = 1000 ml = 0.001 m3) b. Liquid B has a specific gravity of 0.98. How much does 1 L weigh, in an Earth-standard gravitational field? 2. The pipe shown above expands from an internal diameter of 3 cm to an

Projectile Motions

1. What max. initial velocity must a rocket have to reach a target 100 mi away? 2. At what two angles above the horizontal can a projectile be fired in order to reach a distance equal to half the maximum range?

Projectile Motions

A football is thrown with a velocity of 10 m/s at an angle of 30° above the horizontal. (a) What will the time of flight be? (b) How far away should its intended receiver be?

Airplane bomb drop time and impact velocity

An airplane is in level at a velocity of 300 mi/h and an altitude of 5000 ft when it drops a bomb. (a) How long does the bomb take to reach the ground? (b) What will the bomb's velocity be on impact?