Mechanics | Relativity Answers

A fire hose ejects a stream of water at an angle of 30.3° above the horizontal. The water leaves the nozzle with a speed of 20.0 m/s. Assuming that the water behaves like a projectile, how far from a building should the fire hose be located to hit the highest possible fire?

A 710 spacecraft has total energy -0.58 and is in circular orbit around the Sun. Find (a) its orbital radius, (b) its kinetic energy, and (c) its speed

In an experiment to find the mass of a metre rule using the principle of moments, a student first found the centre of mass of the rule to be at the 50cm mark. She then pivoted the rule at the 40cm mark and found a balance for a 200g mass of Plasticine when it was suspended at the 35cm mark. Show the calculation she should now carry out to find the mass of the rule. What was the mass of the rule?

The warranty on a new tire says that an automobile can travel for a distance of 102,000 km before the tire wears out. The radius of the tire is 0.35 m. How many revolutions does the tire make before wearing out?

Two rocks are thrown off the edge of a cliff that is 15.0 m above the ground. The first rock is thrown upward, at a velocity of +12.0 m/s. The second is thrown downward, at a velocity of −12.0 m/s. Ignore air resistance. Determine (a) how long it takes the first rock to hit the ground and (b) at what velocity it hits. Determine (c) how long it takes the second rock to hit the ground and (d) at what velocity it hits.

a 3kg box slides down a 30.0 degree ramp with an acceleration of 1.4 m/sec2. Determine the coefficient of kinetic friction between the box and the ramp.

A 2.10 102-N force is pulling an 70.0-kg refrigerator across a horizontal surface. The force acts at an angle of 17.0° above the surface. The coefficient of kinetic friction is 0.200, and the refrigerator moves a distance of 8.00 m. Find the work done by the kinetic frictional force.

A plane is flying with a constant speed along a straight line at an angle of 30 with the horizontal. The weight W of the plane is 80, 000 N and its engine provides a thrust T of 100, 000 N in the direction of flight. Two additional forces are exerted on the plane: the lift force F perpendicular to the plane’s wings, and the force R due to air resistance opposite to the direction of motion. Draw the free-body diagram showing all forces on the plane. Determine F and R.

6 particles situated at the corners of a regular hexagon of side 'a' move at a constant speed 'v'. each particle maintains a direction towards the particle at the next corner. the time taken 't' by the particles to meet each other is ?

A wagon is pulled by a handle making an upward angle of 25 degrees from the horizontal with a force of 25 N. What is the horizontal force pulling the wagon forward? What is the upward force lifting the wagon off the road?

Show work please, so I can know how to do it.