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gayaneshka [121]
3 years ago
9

Từ độ cao 100 m người ta thả một vật thẳng đứng xuống với v = 10 m/s, g = 10 m/s2 . a. Sau bao lâu vật chạm đất. b. Tính vận tốc

của vật lúc vừa chạm đất.
Physics
2 answers:
kifflom [539]3 years ago
6 0

Câu 1. Một ôtô đang chạy với vận tốc 54km/h thì tài xế hãm phanh, sau 10 giây tốc độ của ôtô là 36km/h.

a) Tìm gia tốc của ôtô?

b) Tìm quãng đường ôtô đi được trong thời gian hãm phanh?

c) Tinh vận tốc của ôtô sau 16 giây kể từ lúc hãm phanh?

Câu 2. Từ độ cao 80m so với mặt đất, thả một vật rơi tự do. Lấy g = 10 m/s2

a) Tính thời gian vật rơi?

b) Tính vận tốc của vật khi chạm đất?

Câu 3. Một vật có khối lượng 500g đang nằm yên, chịu tác dụng một lục 1,2 N, vật chuyển động nhanh dần

đều.

a) Tìm gia tốc của vật?

b) Tìm quãng đường mà vật đi được sau 1 phút?

c) Tính vật tốc của vật sau 30s kể từ lúc bắt đầu chuyển động ?

d) Sau bao lâu kể từ lúc bắt đầu chuyển động, vật có vận tốc 72km/h?

Bas_tet [7]3 years ago
3 0

Answer:

10 points dapat yawa aman daw gud

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pshichka [43]

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<u>Explanation:</u>

<u>Given:</u>

m = 0.5 kg

PE = 50 J

We know that the Potential energy is calculated by the formula:

P. E = m \times g \times h

where m is the is mass in kg;  g  is acceleration due to gravity which is 9.8 m/s  and  h  is height in meters.

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Here, if we substitute the values in the formula, we get

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3 years ago
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Density can be kg/m^3 or g/cm3
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In kg/m3,density=mass/volume. converting mass in grams to kg, 1000g=1kg,111g=0.111kg.
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The 8 kg block is then released and accelerates to the right, toward the 2 kg block. The surface is rough and the coefficient of
natita [175]

Answer:

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As the energy in the system is conserved we have

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The speed of the 8 kg block just before collision is 3.258 m/s

7 0
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yaroslaw [1]

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Now, potential energy at the top is given as:

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Energy to overcome resistance force is the work done by the wrench against the resistance force and is given as:

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Therefore, Kinetic energy at the bottom is given as:

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mariarad [96]

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