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Irina18 [472]
3 years ago
15

While skateboarding at 19 km/h, Alana throws a tennis ball at 11 km/h to her friend Oliver. If Alana is the reference frame, the

speed of the tennis ball is km/h.
Physics
2 answers:
statuscvo [17]3 years ago
3 0
When Alana moving 19km/h, a stationary object will be perceived by her as moving toward her with 19km/h velocity. If the object is not stationary(velocity isn't zero), the speed will increase by the object velocity.

the relative speed of the tennis ball=
the speed of Alana + true speed of the tennis ball
19km/h+ 11km/h= 30km/h
Nastasia [14]3 years ago
3 0

the answer is 11km/h .. i just took the test.

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2 years ago
How much heat must be added to make a 5g substance with a specific heat of 2 J/gC that has its temperature go up 10 degrees? Q =
zlopas [31]

Answer:

100 Joule

Explanation:

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ΔT is the change in the temperature of body

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coming back to problem

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since, it is given that temperature of body increases by 10 degrees, thus

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8 0
3 years ago
If a negative charge is initially at rest in an electric field, will it move toward a region of higher potential or lower potenti
monitta

Answer with explanation :

The negative sign means that the potential energy decreases by the movement of the electron.

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Positive charges will move downhill because of convention. It is to stay in accordance with other potential theories, particularly gravity, where the "charge" is mass, that moves downwards in the gravitational potential field expressed by ϕ(r)=−GM|r|ϕ(r)=−GM|r|. In an electronic system, howbeit, positive charges are fixed in their position within a component (e.g., a wire), therefore instead of the mobile,the negative charges, electrons, move uphill.

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5 0
3 years ago
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