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2 years ago

6

A cricket ball is dropped from a height of 20 m. Calculate: a) the speed of the ball. b) the time it takes to fall through this

height

1 answer:

AysviL [449]2 years ago

7 0

Answer:

Initial velocity is 0 .. ( since it is just dropped)

now using V²= u² +2gh

=> (Vfinal)² = 0+2*10*20

=> v² = 20*20 = 400

=> v = √400 = 20m/s

for time taken

use V = u+gt

=> t = V/g = 20/10 = 2sec

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what would the net force be on the box in the problems shown below.( both force and direction). for all four diagrams. please e

DIA [1.3K]

Answer:
A) object moves 20 N [West] or -20 N [East]
B) object moves 6 N [South] or -6 N [North]
C) object moves 90 N [West] or -90 N [East]
D) object does not move and is at rest*

*Rest means 0

Why:

A)both forces from north and south that are pushing against the object neutralize each other. Assume that north is positive and south is negative: 20 [N] + (-20) [S] = 0
On West and east, you can see that west has a greater force. Assume that west is negative and east is positive: 50 [E] + (-70) [W] = -20 [E]

8 0

3 years ago

If a 20 N object has been lifted 5 meters above the ground, how much gravitational potential energy does it have?

Andreyy89

The gravitational potential energy of the object is 100 J.

Gravitational potential energy stored in an object is the work done in raising the object to a height <em>h</em> against the gravitational force acting on it.

The gravitational force acting on a body is its weight mg, where m is its mass and g, the acceleration due to gravity.

Work done by a force is equal to the product of the force and the displacement made by the point of application of the force.

$GPE = mgh$

The weight of the object is given as 20 J and it is raised to a height of 5 m.

$GPE =(mg)*h = (20 N)*(5m)=100 J$

The gravitational potential energy of the object is 100 J.

5 0

3 years ago

Read 2 more answers

What does the formula "F=m xa" mean?

strojnjashka [21]

Answer:

Force = Mass x Acceleration

Explanation:

5 0

3 years ago

Can you guys please help with this question?

Alexandra [31]

they act as sunshades from the sun intensity, and filters

3 0

3 years ago

I wish to use a step up transformer to turn an initial RMS AC voltage of 100 V into a final RMS AC voltage of 200 V. What is the

zhuklara [117]

Answer:

1:2

Explanation:

It is given that,

Initial RMS AC voltage is 100 V and final RMS AC voltage is 200 V.

We need to find the ratio of the number of turns in the primary to the secondary for step up transformer.

For a transformer, $\dfrac{V_1}{V_2}=\dfrac{N_1}{N_2}$

So,

$\dfrac{N_1}{N_2}=\dfrac{100}{200}\\\\\dfrac{N_1}{N_2}=\dfrac{1}{2}$

So, the ratio of the number of turns in the primary to the secondary is 1:2.

4 0

3 years ago