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3 years ago

3.

Physics

2 answers:

Alborosie3 years ago

4 0

Answer:

Explanation:

Acceleration is defined as a change in velocity over time. This means that as long as the forces are not zero, the velocity should be changing. The can be negative (as this is negative acceleration also known as deceleration) or positive (known as acceleration). It doesn't matter if they are decimals or fractions.

Nookie1986 [14]3 years ago

4 0

In order for acceleration of an object to occur, the sum of the forces must be anything but zero.

Answer: Option C

Explanation:

Based on Newton second laws of motion, the acceleration due to gravity of any object is directly proportional to the net force acting on the object and inversely proportional to the mass of the object. So, the sum of all the forces acting on the object will decide the acceleration attained by the object.

If the total forces are zero then the acceleration of the object will be zero. In case of deceleration, the net force would be having negative sign and thus increase in net force will lead to increase in acceleration. Hence, for the occurrence of acceleration, the total forces sum would be anything but zero.

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The world speed record on water was set on October

Luda [366]

Answer: Remember speed is distance divided by time, so if he travels 1000 m in 7.045 s, his speed is

(1000 m)/(7.045 s) = 141.9 m/s.

Note there are 1609 metres in a mile, or 1 mi = 1609 m, so m = 1/1609 mi, or

141.9/1609 mi/s = 0.08822 mi/s. Now, note that 1 h = 3600 s, so the speed is

0.08822*3600 mi/h = 317.6 mi/h.

8 0

2 years ago

A position vector with magnitude 10 m points to the right and up. its x-component is 6.0 m. part a what is the value of its y-co

lidiya [134]

The position vector can be transcribed as:

A = 6 i + y j

i points in the x-direction and j points in the y-direction.

The magnitude of the vector is its dot product with itself:

|A|2 = A·A

102 = (6 i + y j)•(6 i+ y j) Note that i•j = 0, and i•i = j•j = 1

100 = 36 + y2

64 = y2

get the square root of 64 = 8

The vertical component of the vector is 8 cm.

3 0

2 years ago

brick, dry soil, paper, and water. If all four substances were exposed to sunlight for the same amount of time, which substance

denis-greek [22]

Water because the light is able to enter the water and allow heat to enter faster.

4 0

3 years ago

A 0.12-kg metal rod carrying a current of current 4.1 A glides on two horizontal rails separation 6.3 m apart. If the coefficien

Neporo4naja [7]

Answer:

The magnetic field is $B = 8.20 *10^{-3} \ T$

Explanation:

From the question we are told that

The mass of the metal rod is $m = 0.12 \ kg$

The current on the rod is $I = 4.1 \ A$

The distance of separation(equivalent to length of the rod ) is $L = 6.3 \ m$

The coefficient of kinetic friction is $\mu_k = 0.18$

The kinetic frictional force is $F_k = 0.212 \ N$

The constant speed is $v = 5.1 \ m/s$

Generally the magnetic force on the rod is mathematically represented as

$F = B * I * L$

For the rod to move with a constant velocity the magnetic force must be equal to the kinetic frictional force so

$F_ k = B* I * L$

=> $B = \frac{F_k}{L * I }$

=> $B = \frac{0.212}{ 6.3 * 4.1 }$

=> $B = 8.20 *10^{-3} \ T$

7 0

2 years ago

Water runs out of a horizontal drainpipe at the rate of 135 kg/min. It falls 3.1 m to the ground. Assuming the water doesn't spl

Arlecino [84]

Answer:

The average force exerted by the water on the ground is 17.53 N.

Explanation:

Given;

mass flow rate of the water, m' = 135 kg/min

height of fall of the water, h = 3.1 m

the time taken for the water to fall to the ground;

$h = ut + \frac{1}{2}gt^2\\\\h = 0 + \frac{1}{2}gt^2\\\\t = \sqrt{\frac{2\times 3.1}{9.8} } \\\\t = 0.795 \ s$

mass of the water;

$m = m't\\\\m = 135 \ \frac{kg}{min} \ \times \ 0.795 \ s \ \times \ \frac{1 \ \min}{60 \ s} \ = 1.789 \ kg$

the average force exerted by the water on the ground;

F = mg

F = 1.789 x 9.8

F = 17.53 N

Therefore, the average force exerted by the water on the ground is 17.53 N.

7 0

2 years ago