Suppose that the air resistance encountered by a car is independent of its speed. When the automobile travels at 15 m/s, its engine delivers 20 hp to its wheels. (a) What is the power delivered to the wheels when the automobile travels at 30 m/s? (b) How much power does the automobile use to cover 10 km at 15 m/s? At 30 m/s? Assume that the engine is 25% efficient. (c) Answer the same questions if the strength of the air resistance is proportional to the speed of the car. (d) What do these results, plus your experience with gasoline consumption, tell you about air resistance

Q: How much work must be done to stop a 1100-kg car traveling at 111km / h ? (Hint: You will need to…

A:

Q: I nees help on both problems. I don't know how to start.

A: a) Work done The expression for the force applied on the skier should be equal to the force due to…

Q: 2. A gun fires a bullet vertically upward. The bullet has a mass of 0.02 lbm and leaves the gun at a…

A: Given, Mass of bullet (m)= 0.02lbm  Initial velocity of bullet (u)= 2000ft/s

Q: Two boxes of equal mass are at rest at the same height above the ground. One is dropped straight…

A:

Q: (a) What is the efficiency of an out-of-condition professor who does 2.10×105 J of useful work while…

A: The efficiency can be obtained as

Q: An electric motor is rated to have a maximum power output of 0.83 hp. If this motor is being used to…

A:

Q: An elevator has a mass of 3,000 kg and moves 210 m up in 27 s at constant speed.  At what average…

A: Given m=3000kg x=210m t=27s

Q: How many kilometres per litter will a car obtain if its engine is 25 percent efficient and it…

A: The number of kilometers is,

Q: If the roller coaster car at the top of the 95.0 m drop hill has a speed of 2.25 m/s, (a) what will…

A: Step 1: Step 2: Step 3: Step 4:

Q: A 1,000-W motor powers a hoist used to lift cars at a service station. (a) How much time would it…

A: Power is defined as the work done per unit time. P=Worktime When a mass is raised to some height, we…

Q: A box with a mass of 85kg is sliding horizontially at 17m/s when it reaches a ramp with an incline…

A:

Q: 5. (a) What is the kinetic energy in joules of a 1000kg automobile traveling at 90km/h? (b) How much…

A:

Q: A 618-kg elevator starts from rest and moves upward for 3.10 s with constant acceleration until it…

A: Given Data: The mass of an elevator is, m=618 kg The time required to move upward is, t=3.10 s The…

Q: Suppose that a disk rotates through three revolutions in 4 seconds. a. What is its displacement in…

A: The number of revolutions is The time taken by the disk to rotates 3 rev is

Q: 50. A skier of mass 70 kg is pulled up a slope by a motor- driven cable. (a) How much work is…

A:

Q: Adam drove a bike 1260 m with an average speed of 115m/s. Suppose he applied the brakes to reduce…

A: According to the work-energy theorem, the work done by the brakes will be equal to the change in…

Q: (a) What is the kinetic energy of a 1000 kg automobile traveling at 0.44 km/hr? (b) How much work…

A: Given: mass,  m = 1000 kg  speed,v = 0.44 km/h = 0.122 m/s

Q: A bowling ball is dropped from the top of a building that has a height of ℎ=104m.  (a)Using energy…

A:

Q: At what speed does a 1900 kg compact car have the same kinetic energy as a 20000 kg truck going 24…

A:

Q: In terms of saving energy, bicycling and walking are far more efficient means of transportation than…

A:

Q: In terms of saving energy, bicycling and walking are far more efficient means of transportation than…

A:

Q: A motorcycle can go from 0-60 mph in 3.5 sec.  The mass of the motorcycle is 450 kg.  (a)  What is…

A: The work done is equal to the change in kinetic energy. The power is defined a the rate of doing…

Q: A 684-kg elevator starts from rest and moves upward for 4.20 s with constant acceleration until it…

A: Given: The mass of the elevator is m=684 kg, The cruising speed is vf=1.79 m/s. The time is t=4.20…

Q: A 26-turn circular coil of wire has diameter 1.05 m. It is placed with its axis along the direction…

A:

Q: what speed does a 1100 kg compact car have the same kinetic energy as a 20000 kg truck going 21 km/h…

A:

Q: A skier of mass 70.0 kg rides a ski lift to the top, which is 500 m higher than the base of the…

A: A skier of mass M = 70.0 kg rides a ski lift to the top, which is h = 500 m higher than the base of…

Q: A 694-kg elevator starts from rest and moves upward for 2.80 s with constant acceleration until it…

A: Data Given , Mass of the elevator ( m ) = 694 kg Elevator starts from rest , means  Initial velocity…

Q: A 18,000 kg aircraft is lifted to a height of 12 m. How much potential energy does the aircraft…

A:

Q: Suppose a car travels 108 km at a speed of 25.0 m/s, and uses 1.90 gallons of gasoline. Only 30% of…

A: Given, distance traveled by car, s = 108 kmspeed of the car, v = 25.0 msallons of gasoline used,…

Q: Suppose a car travels 108 km at a speed of 30.0 m/s, and uses 1.90 gallons of gasoline. Only 30% of…

A:

Q: A 607-kg elevator starts from rest and moves upward for 3.90 s with constant acceleration until it…

A: Solution: given that m = 607 kg t = 3.9 s v = 1.67 m/s