A certain car has a drag coefficient of 0.32. If you look at it from the front, the car’s cross section looks roughly like a rectangle that is 1.5 m high by 2.1 m across. What is the engine’s minimum horsepower if its top cruising speed is 42 m/s? Take the density of air to be 1.2 kg/m3.   The engine’s minimum horsepower is _______ hp.

Find the work done by pumping all the oil (density = 794.6 kg / m³) over the edge of a cylindrical tank, which is resting on one of its bases. Suppose the radius of the base is 1.2 m, the height is 3.0 m, and the tank is full of oil. ans. 158687.4008 J

Explain this formula

A 4.00kg block moves with an initial speed of3.50 km/h downhillover an inclined plane as shown in the figure. The height of the inclined plane is 51.3cm and the friction coefficient between the block and the incline is 0.120. a.How much is the speed of the block at the midpoint of the inclined side. b.How much is the speed of the block at the bottom of the inclined side.

A water pump draws water from a pit that is 11.5 m deep at a rate of 685 kg/min. The water ejects above the ground surface at a speed of 20.0m/s, making a vertical fountain. 1. Figure out what the power output is of the pump 2. How high is the fountain? Make sure to Ignore air resistance!

A car engine produces a constant power of P = 341 hp. The car and motor have a combined mass of m = 1830 kg. 1.) The car starts from rest, after t=5 seconds, what is the cars speed, you may assume no energy is required to spin the tires. 2.) Assume a dragster of mass m=1000kg can accelerate to cover  450 m and accelerate in 7.2 s from a dead stop, how much horsepower is the engine producing, assuming acceleration is constant?

A 10-cm-long spring is attached to the ceiling. When a 2.0  kg mass is hung from it, the spring stretches to a length of 15 cm What is the spring constant k? How long is the spring when a 3.2 kg mass is suspended from it?

solve correctly. I will rate accordingly.

I need help with 2a and 2b

A box slides down a plank of length d that makes an angle of θ with the horizontal as shown. μk is the kinetic coefficient of friction and μs is the static coefficient of friction. 1.Enter an expression for the minimum angle θ (in degrees) the box will begin to slide. 2.Enter an expression for the nonconservative work done by kinetic friction as the block slides down the plank. Assume the box starts from rest and θ is large enough that it will move down the plank.  3.For a plank of any length, at what angle θ (in degrees) will the final speed of the box at the bottom of the plank be 0.85 times the final speed of the box when there is no friction present? Assume μk = 0.39.