All categories

2 years ago

Please I need help its timed-

Physics

2 answers:

prohojiy [21]2 years ago

4 0

Answer:c i think

Explanation:

Olenka [21]2 years ago

4 0

Answer:

answer “C” i had that question and it was right for me!!

Explanation:

good luck

You might be interested in

Which kind of energy transformation occurs during skydiving? A) mechanical to gravitational B) gravitational to kinetic C) kinet

Aleks [24]

B) gravitational to kinetic

Explanation:

The skydiver, when he is located at a certain height h above the ground, possesses gravitational potential energy, equal to:

$U=mgh$

where m is the mass of the skydiver, g is the gravitational acceleration and h is the height above the ground. As he falls, its height h decreases, while his speed v increases, so part of the gravitational potential energy is converted into kinetic energy, which is given by

$K=\frac{1}{2}mv^2$

so, we see that as v increases, the kinetic energy increases. Therefore the correct answer is

B) gravitational to kinetic

7 0

3 years ago

Read 2 more answers

Most of the energy released by nuclear fission is in the form of: alpha rays, beta rays, or gamma rays?

Sedbober [7]

I think it is Alpha rays.

3 0

3 years ago

in a tall building, a certain window is 500 meters above the ground.A tennis ball is catapulted horizontally out of the window w

expeople1 [14]

The tennis ball lands at a point 40.4 m from the base of the building.

The tennis ball is projected with a horizontal velocity u from a window, which is at a height y from the ground. The ball lands at a distance x from the base of the building. Let the ball take a time t to reach the ground. In the time t ,the ball falls a vertical distance y and also travel a horizontal distance x.

The initial vertical velocity of the ball is zero, since the ball is projected in the horizontal direction. The ball falls down under the action of gravitational force.

Thus, use the equation of motion,

$y=\frac{1}{2} gt^2$

rewrite the expression for t and calculate the value of t using 9.81 m/s²for g and 500 m for y.

$t=\sqrt{\frac{2y}{g} } \\ =\sqrt\frac{(2)(500m)}{9.81m/s^2} \\ =10.096 s$

The horizontal distance x is traveled using the constant velocity u since no force acts on the ball in the horizontal direction.

Therefore,

$x=ut$

Substitute 4 m/s for u and 10.096 s for t

$x=ut\\ =(4m/s)(10.096s)\\ =40.384m=40.4 m$

Thus, the ball lands at a point 40.4 m from the base of the building.

6 0

3 years ago

The component of the external magnetic field along the central axis of a 18 18 turn circular coil of radius 27.0 27.0 cm decreas

madreJ [45]

Answer:

Induced current I = 0.44 A

Explanation:

given data

no of turn N = 18

radius = 27.0 cm

resistance of the coil = 4.50 Ω

time = 2.90 s

magnetic field = 1.90 T to 0.500 T

solution

we get Induced EMF that is

E = - dφ ÷ dt ..............1

E = - N × A × (B2 - B1) ÷ Δt

E = N × A × (B1 - B2) ÷ Δt

area of cross section of the coil A = π × r²

area of cross section = 3.14 × (0.27)²

area of cross section = 0.228 m²

Initial magnetic field B1 = 1.9 T

and

Final magnetic field B2 = 0.5 T

time Δt = 3.7 s

put here value and we get

E = $\frac{18 \times 0.228 \times (1.9-0.5)}{2.90}$

E = 1.98 V

and

Induced current I is express as

Induced current I = E ÷ R ................2

Induced current I = $\frac{1.98}{4.5}$

Induced current I = 0.44 A

3 0

2 years ago

The coefficients of static and kinetic friction between a 3.0-kg box and a horizontal desktop are 0.40 and 0.30, respectively. w

luda_lava [24]

The force of friction on the box is 8.82 N.

The force of friction is given by the formula

F=μN

Here N is the normal force of the box=mg=3*9.8=29.4 N

Now the static friction force on the box is=0.4*29.4=11.76 N

Since the box is applied with the horizontal pull of 15 N, which is greater than the static friction, therefore the box must be in the moving condition, in that case there is dynamic friction force is applied on the box=0.3*29.4=8.8 N

Therefore the force of friction on the box is 8.8 N.

6 0

3 years ago