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3 years ago

You lift a 10-N physics book up in the air a distance of 1.0 m, at a constant velocity

1 answer:

5 0

The book is lifted upward, but gravity points down, so the work done by gravity must be negative (so you can eliminate options 1 and 3).

The force exerted on the book by gravity has magnitude

<em>F</em> = <em>mg</em> = (10 N) (9.80 m/s^2) = 9.8 N ≈ 10 N

You raise the book 1.0 m in the opposite direction, so the work done is

<em>W</em> = (10 N) (-1.0 m) = -10 J

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Which contains the particles that are vibrating fastest?

Phantasy [73]

Answer:

Boiling water

Explanation:

3 0

2 years ago

A motorboat traveling with a current can go 160 km in 4 hours. against the current it takes 5 hours to go the same distance. Fin

MatroZZZ [7]

<h2>Speed of motorboat is 36 km/hr and speed of current is 4 km/hr.</h2>

Explanation:

Let speed of motor boat be m and speed of current be c.

A motorboat traveling with a current can go 160 km in 4 hours.

Distance = 160 km

Time = 4 hours

Speed = m + c

We have

Distance = Speed x Time

160 = (m+c) x 4

m + c = 40 --------------------- eqn 1

Against the current it takes 5 hours to go the same distance.

Distance = 160 km

Time = 5 hours

Speed = m - c

We have

Distance = Speed x Time

160 = (m-c) x 5

m - c = 32 --------------------- eqn 2

eqn 1 + eqn 2

2m = 40 + 32

m = 36 km/hr

Substituting in eqn 1

36 + c = 40

c = 4 km/hr

Speed of motorboat is 36 km/hr and speed of current is 4 km/hr.

3 0

3 years ago

Find the force between 2C and -1C separated by a distance 1m. Indicate if it is an attractive force (negative) or a repulsive fo

telo118 [61]

Answer:

Explanation:

Its definitely an Attractive force since the two charges are Unlike.

From Coulombs Law

F=kq1q2/R²

Given

K=9x10^9

R=1m

q1=2C

q2=-1C

F=(9x10^9 x 2 x -1)/1²

F= - 1.8x10^10N. (Attractive).

6 0

3 years ago

for much of the year this desert is hot dry and windy.What type of plant would you most expect to survive in this climate

abruzzese [7]

I think the answer is cactus

7 0

3 years ago

The magnitude of displacements a and b are 3m and 4m, respectively, c=a+b. What is the magnitude of c if the angel between a and

AysviL [449]

Answer:

(a) 7 m

(b) 1 m

Explanation:

Given:

The magnitude of displacement vector 'a' is 3 m

The magnitude of displacement vector 'b' is 4 m.

The vector 'c' is the vector sum of vectors 'a' and 'b'.

(a)

Now, when the angle between the vectors is 0°, it means that the vectors are in the same direction. When vectors are in the same direction, then their resultant magnitude is simply the sum of their magnitudes.

So, magnitude of 'c' when 'a' and 'b' are in same direction is given as:

$|\overrightarrow c|=|\overrightarrow a|+|\overrightarrow b|\\\\|\overrightarrow c|=3 + 4 = 7\ m$

Therefore, the magnitude of vector 'c' is 7 m when angle between 'a' and 'b' is 0°.

(b)

When the angle between the vectors is 180°, it means that the vectors are exactly in the opposite direction. When the vectors are in opposite direction, then their resultant magnitude is the subtraction of their magnitudes.

So, magnitude of 'c' when 'a' and 'b' are in opposite direction is:

$|\overrightarrow c|=||\overrightarrow a|-|\overrightarrow b||\\\\|\overrightarrow c|=|3 - 4| = 1\ m$

Therefore, the magnitude of vector 'c' is 1 m when angle between 'a' and 'b' is 180°.

4 0

3 years ago