Một vật có khối lượng 100g, động năng 1J, g = 10m/$s^{2}$. Tính vận tốc của vật.

2 câu trả lời

 m =100 g= 0,1 kg

 $W_{đ}$ = 1J

 $W_{đ}$ = $\frac{1}{2}$ .m.$v^{2}$

  ⇒ v = $\sqrt[]{\frac{2  W_{đ}}{m}}$  = 2$\sqrt[]{5}$ m/s

 

Đáp án:

$v = 2\sqrt 5 m/s$

Giải thích các bước giải:

Vận tốc của vật là:
$W = \dfrac{1}{2}m{v^2} \Leftrightarrow v = \sqrt {\dfrac{{2W}}{m}}  = \sqrt {\dfrac{{2.1}}{{0,1}}}  = 2\sqrt 5 m/s$

Câu hỏi trong lớp Xem thêm

Mark the letter A, B, e,or D to indicate the underlined part that needs correction in each of the following questions. ( sửa lỗi luôn ạ) 51. A lot of people think that marriage women shouldn't pursue a career. A B C D 52. We must stop discrimination on people coming from the rural area. A B C D 53. My brother is good with cooking and he can cook very delicious food. A B C D 54. I guess they may be kept home doing housework and look after their chifdren, A B C D 55. Women in rural areas might be forced to work both at home but on the fields. A B C D 56. Some people think that girls shouldn't be allowed to going to university. A B C D 57. Gender discrimination should be eliminated for create equal opportunities in educationfor everyone. A B C D 58. More girls should being chosen to represent us in the School Youth Union .. A B C D 59. Both women and men should be given equal rights for education and employment. A B C D 60. This discrimination against women and girls must be abolishing. A B C D 61. Efforts should be make to offer all children equal access to education. A B C D 62. It is clear that gender differences cannot prevent a person to pursue a job. A B C D 63. Traditional women were mainly responsible to doing housework and looking after their husbands and A B C D children. 64. Doing houseworkevery day is really boring and tired. A B C D 65. In the past, women was often passive and dependent on their husbands. A B C D 66. Women usually get less pay as men for doing the same job. A B C D

0 lượt xem
2 đáp án
13 giờ trước