## Physics for the Life

Physics & Astronomy

## Quiz 7 :

Energy and Its Conservation

Looking for Introductory Physics Homework Help?

Q06 Q06 Q06

You are walking a dog on a leash, pulling it with a force of 40 N. The leash is continuously acting on the dog's body at an angle of 115° with respect to the direction of motion. Which of the following is the value for the work of the tension in the leash after 100 m?

Free

Unlocked

Multiple Choice

Q15 Q15 Q15

You want to climb to the top of a wall that is 2.0 m high, using a ramp. You have a choice of several arrangements for the ramp regarding the length and the angle. Which of the following arrangements would you choose to climb to the top so that you do the least work?

Free

Unlocked

Multiple Choice

Q16 Q16 Q16

You want to climb to the top of a 2.0 m high wall using a ramp. You have a choice of several arrangements for the ramp regarding the length and the angle. Which one of these arrangements would you choose in order to climb to the top with the least "energy consumption in time" (power)?

Free

Unlocked

Multiple Choice

Q20 Q20 Q20

Two skiers starting from the same point go downhill without breaking. They choose two different paths to the bottom of the slope: One goes straight down the steepest slope, the other chooses the longer less steep path. Which skier will have the higher speed at the bottom?

Free

Unlocked

Multiple Choice

Q40 Q40 Q40

A standard man with a mass of 70 kg runs on a treadmill at a constant velocity of 5 m/s, exerting a constant force F

_{man}= 600 N up the 25° slope of a treadmill, for 6 minutes. The coefficient of kinetic friction of a treadmill is ì = 0.40. What is the work done by the standard man?Free

Unlocked

Essay

Q42 Q42 Q42

Canadian golf champion Jason Zuback achieved record speed of the ball, hitting it to 328 km/h. If he hit a 46 g ball at an angle of 45° for maximal range, what is the kinetic energy at the top of the trajectory? How does that compare to the kinetic energy when the ball was hit?

Free

Unlocked

Essay

Q46 Q46 Q46

Figure 7.4 The figure shows an object attached to a string, making a pendulum.
-A ball of mass 5 kg is attached to a string of length 2 m, as shown in Fig. 7.4. If we release the ball at an angle of 85°, and let it hit a stationary ball of mass 10 kg at the bottom of its trajectory, what is the speed of each ball after the collision? Assume the collision is elastic.

Free

Unlocked

Essay