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Ymorist [56]
3 years ago
5

A crane lifts a concrete block, whose weight is 60,000N to a height of 20m in 30s.

Physics
1 answer:
Nataly_w [17]3 years ago
7 0

Answer:

C

Explanation:

Power formula is power=work(joules)/time(seconds). the Work formula is force (newtons) times the distance from the starting point. Calculate work first: 60,000N x20m = 1,200,000 joules. Then plug into power formula: 1,200,000j/ 30 seconds= 40,000 W

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The speed of a 180-g toy car at the bottom of a vertical circular portion of track is 7.75 m/s. If the radius of curvature of th
Bezzdna [24]

Answer:

11.28 N toward the center of the track

Explanation:

Centripetal force: This is the force that tend to draw a body close to the center of a circle, during circular motion.

The formula for centripetal force is given as,

F = mv²/r................................ Equation 1

Where F = force, m = mass of the toy car, v = velocity, r = radius

Given: m = 108 g = 0.108 kg, v = 7.75 m/s, r = 57.5 cm = 0.575 m

Substitute into equation 1

F = 0.108(7.75²)/0.575

F = 11.28 N

Hence the magnitude and direction of the force = 11.28 N toward the center of the track

7 0
3 years ago
A 4kg block and a 2kg block can move on horizontal frictionless surface. The blocks are accelerated by a +12-N force that pushes
Stolb23 [73]

Answer:

a) -4 N

b) +4 N

Explanation:

Draw a free body diagram for each block.

For the large block, there are 2 forces: 12 N pushing to the right, and F pushing to the left.

For the small block, there is 1 force, F pushing to the right.

There are also weight and normal forces in the vertical direction, but we can ignore those.

Sum of forces on the large block in the x direction:

∑F = ma

12 − F = 4a

Sum of forces on the small block in the x direction:

∑F = ma

F = 2a

2F = 4a

Substitute:

12 − F = 2F

12 = 3F

F = 4

The small block pushes on the large block 4 N to the left (-4 N).

The large block pushes on the small block 4 N to the right (+4 N).

4 0
3 years ago
A student drew the following model:
Gelneren [198K]

Answer: C Tectonic Plates

Explanation:

8 0
4 years ago
Read 2 more answers
The colors you see during a sunset are caused by _____. the refraction of light by the atmosphere the absorption of light by the
love history [14]

Answer: the refraction of light by the atmosphere

Explanation: Refraction is the phenomenon in which there is a change in direction of light passing from one medium to another or from a gradual change in the medium.

Here in case of sunset, the sun rays passes through the varying density of atmosphere because of varying concentrations of dust particles.

Reflection is the phenomenon in which the light bounces back after falling on a surface.

Absorption is the phenomenon in which matter captures the electromagnetic radiations and thus the energy of photons is converted to internal energy of the system.

6 0
3 years ago
1. Determine the image distance in each of the following.
miskamm [114]

It is given that for the convex lens,

Case 1.

u=−40cm

f=+15cm

Using lens formula

v

1

−

u

1

=

f

1

v

1

−

40

1

=

15

1

v

1

=

15

1

−

40

1

v=+24.3cm

The image in formed in this case at a distance of 24.3cm in left of lens.

Case 2.

A point source is placed in between the lens and the mirror at a distance of 40 cm from the lens i.e. the source is placed at the focus of mirror, then the rays after reflection becomes parallel for the lens such that

u=∞

f=15cm

Now, using mirror’s formula

v

1

+

u

1

=

f

1

v

1

+

∞

1

=

15

1

v=+15cm

The image is formed at a distance of 15cm in left of mirror

6 0
3 years ago
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