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3 years ago

PLEASE HLEP ME ASAP

Physics

1 answer:

bija089 [108]3 years ago

3 0

Answer:

cardiovascular endurance

Explanation:

In order for Tom to successfully complete the marathon, he should focus on being able to maintain a constant pace without tiring easily.

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A camera takes a properly exposed photo with a 4.0 mm diameter aperture and a shutter speed of 1/1000 s. If the photographer foc

hoa [83]

Answer:

option E

Explanation:

given,

diameter = 4 mm

shutter speed = 1/1000 s

diameter of aperture = ?

shutter speed = 1/250 s

exposure time to the shutter time

$E V = log_2(\dfrac{N^2}{t})$

N is the diameter of the aperture and t is the time of exposure

now,

$log_2(\dfrac{N^2}{t_1})=log_2(\dfrac{N^2}{t_2})$

$\dfrac{N_1^2}{t_1}=\dfrac{N_2^2}{t_2}$

inserting all the values

$\dfrac{4^2}{1000}=\dfrac{N_2^2}{250}$

N₂² = 4

N₂ = 2 mm

hence , the correct answer is option E

4 0

3 years ago

Can someone help me with this real quick?

ch4aika [34]

Answer:

7,546 J

Explanation:

recall that Potential energy is given by

P.E = mgΔh

where m = 70kg (given)

g = 9.8 m/s² (acceleration due to gravity)

Δh = change in height

= distance from top of building to top of car

= height of building - height of car

= (5+8) - 2

= 11m

substituting all these into the equation:

P.E = mgΔh

= 70 x 9.8 x 11

= 7,546 J

4 0

3 years ago

The recoil of a shotgun can be significant. Suppose a 3.6-kg shotgun is held tightly by an arm and shoulder with a combined mass

devlian [24]

Answer:

The velocity of the recoil is $v=1.001 \frac{m}{s}$

Explanation:

Kinetic Energy

$m_{bullet}*v_{bullet}=m_{gun}*v_{recoil}\\m_{gun}= 15.0kg+3.6kg$

The mass of th gun is the both mass the shotgun and the arm shoulder combination

$m_{bullet}=0.049kg\\v_{bullet}=380\frac{m}{s} \\m_{bullet}*v_{bullet}=m_{gun}*v_{recoil}\\0.049kg*380\frac{m}{s}=(15.kg+3.6kg)* v_{recoil}\\v_{recoil}=-\frac{18.62 kg \frac{m}{s} }{18.6 kg}\\ v_{recoil}=-1.0010 \frac{m}{s}$

The velocity is negative because is in opposite direction of the bullet

6 0

2 years ago

Read 2 more answers

A force of 50 N ,at an angle of 20°,was applied while pulling a 30 kg sled horizontally across the snow. If 939.69 J of work was

artcher [175]

Answer:

20m

Explanation:

w = f × d

= (50cos20) × d

therefore, d = 20m

6 0

2 years ago

A parachutist weighs 1000N. when she opens her parachute, it pulls upwards on her with a force of 2000N. (a) draw a diagram to s

Nataly_w [17]

(a) Find free-body diagram in attachment (please rotate the picture, such that R points upward and mg points downward)

There are only two forces acting on the parachutist:

- Its weight, downward, of magnitude 1000 N, labelled with "mg" in the diagram (where m = mass of the parachutist, g = acceleration of gravity)

- The air resistance, upward, of magnitude 2000 N, labelled with "R" in the diagram

As the air resistance is larger than the weight, in the diagram it is represented with a longer arrow, in order to show the difference in magnitude.

(b) 1000 N, upward

By taking upward as positive direction, we can rewrite the two forces as:

R = +2000 N

mg = -1000 N

Where we have written the weight as a negative number, since its direction is downward.

Therefore, the net force on the parachutist will be

F = R + mg = +2000 + (-1000) = +1000 N

And the positive sign indicates that the resultant force is upward.

(c) The parachutist will be accelerated upward (= he/she will slow down)

We can answer this part by applying Newton's second law, which is summarized by the following:

$F=ma$ (1)

where

F is the resultant force on the body

m is its mass

a is its acceleration

For the parachutist in this problem, the mass is

$m=\frac{mg}{g}=\frac{1000 N}{9.8 N/kg}=102 kg$

Therefore, using (1), we find the acceleration of the parachutist:

$a=\frac{F}{m}=\frac{+1000}{102}=+9.8 m/s^2$

Where the positive sign indicates that the acceleration is upward. Therefore, the parachutist will be accelerated upward, which means that he/she will slow down, since its direction of motion was downward.

4 0

3 years ago