(a) the high of a hill that car can coast up (engine disengaged) if work done by friction is negligible and its initial speed is 110 km/h is 47.6 m

(b) thermal energy was generated by friction is 1.88 x $10^{5}$ J

(C) the average force of friction if the hill has a slope 2.5º above the horizontal is 373 N

Explanation:

given information:

m = 750 kg

initial velocity, $v_{0}$ = 110 km/h = 110 x 1000/3600 = 30.6 m/s $\frac{30.6^{2} }{2x9.8}$

initial height, $h_{0}$ = 22 m

slope, θ = 2.5°

(a) How high a hill can a car coast up (engine disengaged) if work done by friction is negligible and its initial speed is 110 km/h?

according to conservation-energy

EP = EK

mgh = $\frac{1}{2} mv_{0} ^{2}$

gh = $\frac{1}{2} v_{0} ^{2}$

h = $\frac{v_{0} ^{2} }{2g}$

= 47.6 m

(b) If, in actuality, a 750-kg car with an initial speed of 110 km/h is observed to coast up a hill to a height 22.0 m above its starting point, how much thermal energy was generated by friction?

thermal energy = mgΔh

= mg (h - $h_{0}$ )

= 750 x 9.8 x (47.6 - 22)

= 188160 Joule

= 1.88 x $10^{5}$ J

(c) What is the average force of friction if the hill has a slope 2.5º above the horizontal?

f d = mgΔh

f = mgΔh / d,

where h = d sin θ, d = h/sinθ

therefore

f = (mgΔh) / (h/sinθ)

= 1.88 x $10^{5}$ /(22/sin 2.5°)

= 373 N

8 0

3 years ago

Which statement is the best interpretation of the ray diagram shown below?

madreJ [45]

A) A concave mirror forming a larger, virtual image

Explanation:

The figure is missing; see attachment.

There are two types of mirror:

Concave (converging) mirrors: a concave mirror is a mirror that reflects the light inward
Convex (diverging) mirrors: a convex mirror is a mirror that reflects the light outward

The image formed by a mirror can also be of two types:

Real image: it is formed on the same side of the object, with respect to the mirror
Virtual image: it is formed on the opposite side of the object, with respect to the mirror

In the figure of this problem (see attachment), we see that:

- The mirror reflects the light from the object inward --> so it is a concave mirror

- The image is formed on the other side of the mirror --> it is a virtual image

So the correct option is

A) A concave mirror forming a larger, virtual image

Learn more about mirrors:

brainly.com/question/8737441

#LearnwithBrainly

7 0

3 years ago

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A child kicks a ball horizontally with a speed of 4.8 m/s off a deck 3.5 m off the ground. How far, in meters, from the deck doe

Vesna [10]

Answer:

2.605m

Explanation:

Using the formula for calculating Range (distance travelled in horizontal direction)

Range R = U√2H/g

U is the speed = 4.8m/s

H is the maximum height = ?

g is the acc due to gravity = 9.8m/s²

R = 3.5m

Substitute into the formula and get H

3.5 = 4.8√2H/9.8

3.5/4.8 = √2H/9.8

0.7292 = √2H/9.8

square both sides

0.7292² = 2H/9.8

2H = 0.7292² * 9.8

2H = 5.21

H = 5.21/2

H = 2.605m

Hence the height of the ball from the ground is 2.605m

7 0

2 years ago

What is the most commonly used method of food preservation today? refrigeration drying foods smoking raw meats salt curing

dmitriy555 [2]

Refrigerator was what is commonly used today. We do dry foods and salt cure but that is not done on a daily basis

6 0

3 years ago

Read 2 more answers