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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

F = mg = (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

W = (10 N) (-1.0 m) = -10 J

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A 20 m high filled water tank develops a 0.50 cm hole in the vertical wall near the base. With what speed does the water shoot o

Rina8888 [55]

Answer:

The speed of the water shoot out of the hole is 20 m/s.

(d) is correct option.

Explanation:

Given that,

Height = 20 m

We need to calculate the velocity

Using formula Bernoulli equation

$\dfrac{1}{2}\rho v_{1}^2+\rho gh_{1}=\dfrac{1}{2}\rho v_{2}^2+\rho gh_{2}$

Where,

v₁= initial velocity

v₂=final velocity

h₁=total height

h₂=height of the hole from the base

Put the value into the formula

$v_{1}^2=2g(h_{2}-h_{1})$

$v_{1}=\sqrt{2g(h_{2}-h_{1})}$

$v_{1}=\sqrt{2\times9.8\times(20-0.005)}$

$v_{1}=19.7\ m/s= approximate\ 20\ m/s$

Hence, The speed of the water shoot out of the hole is 20 m/s.

7 0

3 years ago

An object has an average acceleration of +6.18 m/s2 for 0.266 s . At the end of this time the object's velocity is +9.90 m/s .

Archy [21]

At the start of the 0.266 s, the object's speed was 8.26 m/s.

The question can only be talking about speed, not velocity.

4 0

3 years ago

If you want to conduct an electrical current, which situation would produce a solution capable of this? A) Dissolving water in o

svp [43]

D dissolving solid NaF in water

6 0

3 years ago

Read 2 more answers

A physical science test book has a mass of 2.2kg. . What is the weight on the earth

dem82 [27]

Weight = mg, g ≈ 9.8 m/s²

Weight = 2.2 * 9.8 ≈ 21.56 N

8 0

4 years ago

Read 2 more answers

7. A beam of light converges at a point P. Now a lens is placed in the path of the convergent

Rudiy27

Answer:

Lens at a distance = 7.5 cm

Lens at a distance = 6.86 cm (Approx)

Explanation:

Given:

Object distance u = 12 cm

a) Focal length = 20 cm

b) Focal length = 16 cm

Computation:

a. 1/v = 1/u + 1/f

1/v = 1/20 + 1/12

v = 7.5 cm

Lens at a distance = 7.5 cm

b. 1/v = 1/u + 1/f

1/v = 1/16 + 1/12

v = 6.86 cm (Approx)

Lens at a distance = 6.86 cm (Approx)

5 0

3 years ago