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
kenny6666 [7]
2 years ago
13

A person is standing on and facing the front of a stationary skateboard while holding a construction brick. The mass of the pers

on is 68.0 kg, the mass of the skateboard is 4.10 kg, and the mass of the brick is 2.50 kg. If the person throws the brick forward (in the direction they are facing) with a speed of 21.0 m/s relative to the skateboard and we ignore friction, determine the recoil speed of the person and the skateboard, relative to the ground.
Physics
1 answer:
jek_recluse [69]2 years ago
4 0

Answer:

0.74 m/s

Explanation:

From the question,

We apply the law of conservation of momentum,

Total momentum before collision = Total momentum after collision.

Since the skateboard, the person and the brick where stationary, therefore, the total momentum before collision is 0

0 = Total momentum after collision

(m+M)V + m'v = 0

Where m = mass of the  skateboard, M = mass of the person, m' = mass of the brick, V = recoil velocity of the person and the skateboard, v =  velocity of the brick

make V the subject of the equation above

V = -m'v/(m+M)................... Equation 1

Given: m = 4.10 kg, M = 68.0 kg, m' = 2.50 kg, v = 21.0 m/s.

Substitute these values into equation 1

V = -(2.5×21)/(68+2.5)

V = 52.50/70.5

V = 0.74 m/s

You might be interested in
The interest rate that the Fed charges banks that borrow money from it is called A. the discount rate. B. the federal rate. C. t
son4ous [18]
The answer is A. the discount rate.
7 0
2 years ago
Read 2 more answers
If the area of an iron rod is 10 cm by 0.5 cm and length is 35 cm. Find the value of resistance, if 11x10^-8 ohm.m be the resist
malfutka [58]

Answer:

Resistance of the iron rod, R = 0.000077 ohms    

Explanation:

It is given that,

Area of iron rod, A=10\ cm\times 0.5\ cm=5\ cm^2 = 0.0005\ m^2

Length of the rod, L = 35 cm = 0.35 m

Resistivity of Iron, \rho=11\times 10^{-8}\ \Omega-m

We need to find the resistance of the iron rod. It is given by :

R=\rho\dfrac{L}{A}

R=11\times 10^{-8}\times \dfrac{0.35\ m}{0.0005\ m^2}

R=0.000077 \Omega

So, the resistance of the rod is 0.000077 ohms. Hence, this is the required solution.

6 0
2 years ago
An inductor of inductance 0.02H and capacitor of capacitance 2 microF are connected in series to an AC source of frequency 200/p
Ad libitum [116K]
C because it’s not a or B so 50/50 c or d and d is def not the answer so c
5 0
2 years ago
The hot glowing surfaces of stars emit energy in the form of electromagnetic radiation. It is a good approximation to assume tha
belka [17]

Given that,

Energy H=2.7\times10^{31}\ W

Surface temperature = 11000 K

Emissivity e =1

(a). We need to calculate the radius of the star

Using formula of energy

H=Ae\sigma T^4

A=\dfrac{H}{e\sigma T^4}

4\pi R^2=\dfrac{H}{e\sigma T^4}

R^2=\dfrac{H}{e\sigma T^4\times4\pi}

Put the value into the formula

R=\sqrt{\dfrac{2.7\times10^{31}}{1\times5.67\times10^{-8}\times(11000)^4\times 4\pi}}

R=5.0\times10^{10}\ m

(b). Given that,

Radiates energy H=2.1\times10^{23}\ W

Temperature T = 10000 K

We need to calculate the radius of the star

Using formula of radius

R^2=\dfrac{H}{e\sigma T^4\times4\pi}

Put the value into the formula

R=\sqrt{\dfrac{2.1\times10^{23}}{1\times5.67\times10^{-8}\times(10000)^4\times4\pi}}

R=5.42\times10^{6}\ m

Hence, (a). The radius of the star is 5.0\times10^{10}\ m

(b). The radius of the star is 5.42\times10^{6}\ m

8 0
3 years ago
Which of the following statements best describes the method of energy conservation known as cogeneration?
Mazyrski [523]

Answer:

heat and power

Explanation:

is the simultaneous production of electricity and heat both of which are used

6 0
2 years ago
Other questions:
  • Match the player positions with his or her job on the court.
    6·2 answers
  • An unstrained horizontal spring has a length of 0.39 m and a spring constant of 350 N/m. Two small charged objects are attached
    6·1 answer
  • Jim is driving a 2268-kg pickup truck at 30.0m/sand releases his foot from the accelerator pedal. The car eventually stops due t
    8·1 answer
  • Mary and her younger brother Alex decide to ride the carousel at the State Fair. Mary sits on one of the horses in the outer sec
    13·1 answer
  • What is meant by "steam distillation"? choose the correct option from below.
    14·1 answer
  • May someone please help me with this The ability to perceive accurately, appraise, and express emotion is called
    10·2 answers
  • A car traveled 60km in 45 min.What is the cars average speed in km/hr
    10·1 answer
  • Which of ONE of the following four elements has the most metallic properties?
    15·1 answer
  • Alkaline earth metals have a low density<br><br><br> true<br> false
    7·1 answer
  • In a skate park, you are trying to determine how to get the most speed at the bottom of the ramp. If the ramp is 4.5 m high, and
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!