1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
tiny-mole [99]
3 years ago
7

A 87 kg man has a total mechanical energy of 1780 J .If he is swinging downward and is currently 1.4 m above the ground, what is

his speed? Use g = 10 m/s^2
Physics
1 answer:
borishaifa [10]3 years ago
4 0

Answer:

6.4m/s

Explanation:

The total mechanical energy of the man is 1780J.

This mechanical energy is the energy due to the motion of the body and it is a form of kinetic energy.

 Also, mass  = 87kg

   Kinetic energy  = \frac{1}{2}   m v²

m is the mass

v is the velocity

           1780  =  \frac{1}{2} x 87 x v²

                v²  = 40.9

                v  = 6.4m/s

You might be interested in
A football punker attempts to kick the football so that it lands on the ground 67.0 m from where it is kicked and stays in the a
Flauer [41]

To solve this problem we will apply the linear motion kinematic equations. We will find the two components of velocity and finally by geometric and vector relations we will find both the angle and the magnitude of the vector. In the case of horizontal speed we have to

v_x = \frac{x}{t}

v_x = \frac{67}{4.5}

v_x = 14.89m/s

The vertical component of velocity is

-h = v_y t -\frac{1}{2} gt^2

Here,

h = Height

g = Gravitational acceleration

t = Time

v_y = Vertical component of velocity

-1.23 = v_y(4.5)-\frac{1}{2} (9.8)(4.5)^2

-1.23= 4.5v_y - 99.225

v_y = 21.77m/s

The direction of the velocity will be given by the tangent of the components, then

tan\theta = \frac{v_y}{v_x}

\theta = tan^{-1} (\frac{21.77}{14.89})

\theta = 55.59\°

The magnitude is given vectorially as,

|V| = \sqrt{v_x^2+v_y^2}

|V| = \sqrt{14.89^2 +21.77^2}

|V| = 26.37m/s

Therefore the angle is 55.59° and the velocity is 26.37m/s

6 0
3 years ago
TRUE OR FALSE! PLZ HELP
Ksju [112]

Answer:

True

Explanation:

Magnitude is the "value" the greater the value the greater the force is and vice versa

5 0
2 years ago
What wavelength of light (in nm) is associated with a frequency of 8.01E15 Hz?
AlekseyPX

Answer: 37.5 nm

Explanation: speed of light c= 3.00·10^8 m/s.

I use same accuracy to speed of light as it's for frequency.

Frequency f= 8.01·10^15 1/s

Speed c = wavelength · frequency

Wavelength = c/f = 3.745·10^-8 m

6 0
3 years ago
A 350-N child is in a swing that is attached to a pair of ropes 2.10 m long. Find the gravitational potential energy of the chil
o-na [289]

Answer:

a)  U = 735 J , b) U = 125.7 J , c)   U = 0 J

Explanation:

The gravitational power energy is

      U = mg y - mg y₀

The last value is a constant, for simplicity we can make it zero, if the lowest point is at the origin of the coordinate system, which in this case we will place in the lowest part

a) Rope is horizontal

The height in this case is the same length of the rope

     y = 2.10 m

    w = mg = 350 N

    U = 350 2.10

    U = 735 J

b) when the angle is 34º

     y = L - L cos 34

    y = L (1- cos34)

    y = 2.10 (1- cos 34)

    y = 0.359 m

    U = 350 0.359

    U = 125.7 J

c) in this case this point coincides with the reference system

     y = 0

     U = 0 J

4 0
4 years ago
A centripetal force causes circular motion because it accelerates an object
MAVERICK [17]

The answer is option A.

Centripetal force is always directed towards the centre and does not change the speed of the body,but there is a change in the direction.

6 0
4 years ago
Read 2 more answers
Other questions:
  • Formula for potassium phosphate
    14·1 answer
  • A black, totally absorbing piece of cardboard of area A = 1.7 cm2 intercepts light with an intensity of 8.1 W/m2 from a camera s
    11·2 answers
  • The atmospheric temperature decreases when snow starts melting because the snow releases thermal energy from the atmosphere to m
    14·2 answers
  • What is the lowest level of waves on the electromagnetic energy spectrum?
    7·1 answer
  • A fugitive tries to hop on a freight train traveling at a constant speed of 5.2 m/s . Just as an empty box car passes him, the f
    5·1 answer
  • Objects fall at constant velocity
    12·2 answers
  • What is brownion motion
    12·1 answer
  • When you look at a star, where in space are you looking?
    5·2 answers
  • A bowling ball moves 18 meters every 2 seconds down the lane at a bowling alley. What is the speed of the bowling ball?
    7·1 answer
  • Condyloid joints are, logically enough, created by joints at condyle bone markings.
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!